file which includes the numerous        
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#fcabh-;h4htm or #fcabh-;h4zip3         
7https3_/_/www4gutenberg4org_/cache_/epu
b_/#fcabh_/pg#fcabh-;images4html7       
or                                      
7https3_/_/www4gutenberg4org_/files_/#fc
abh_/fcabh-;h4zip7         ,images of   
the original pages are available through
       ,internet ,archive4 ,see         
https3_/_/archive4org_/details_/rudiment
arytreat#jj;hobb   ,transcriber's note3 
,text enclosed by underscores is in     
italics 7italics74        ,small        
capitals have been transcribed as ,,all 
,,capitals4        ,a detailed          
transcriber's note can be found at the  
end of       this text4                 
,,rudimentary ,,treatise ,,on ,,the     
,,construction ,,of ,,locks4   ,london3 
,printed by ,levey1 ,robson1 and        
,franklyn1 ,great ,new ,street and      
,fetter ,lane4     ,,rudimentary        
,,treatise ,,on ,,the ,,construction    
,,of ,,locks4  ,edited by  ,,charles    

,,tomlinson4   8,il n'y a point de      
machines plus communes que les serrures3
 elles sont assez composes pour mriter  
le nom de machine2 mais je ne sais s'il 
y en a qui soient aussi peu connues par 
ceux qui les emploient4 ,il est rare    
qu'on sache en quoi consiste la bont    
d'une serrure1 le degr de sret qu'on    
peut s'en promettre4 ,leur extrieur est 
presque la seule chose  quoi l'on       
s'arrte4 ,les usages importans auxquels 
elles sont employes devraient cependant 
exciter la curiosit  les connatre1 si la
 curiosit tait toujours excite          
raisonnablement40--,m4 ,,de ,r,,aumur1  
8,des ,serrures de toutes les espces10  
forming the fifth chapter of ,m4        
,duhamel's ,treatise 8,art du           
,serrurier10 in the 8,descriptions des  
,arts et ,metiers faites ou approuves   
par ,messieurs de l',acadmie ,royale des
 ,sciences40       ,london3 ,john       
,weale1 #ei ,high ,holborn4 ,,mdcccliii4
       8,there are no machines more     
common than locks3 they are sufficiently

   complex to merit the name of machine2
 but ,i know of no others the           
structure of which is so little         
understood by those who use them4 ,it   
is rare to find any one who knows       
wherein the goodness of a lock          
consists1 or the degree of security that
 he can attach to it4 ,the   outside of 
a lock is usually all that attracts     
attention4 ,doubtless   the important   
uses to which locks are applied would   
excite curiosity   respecting their     
structure1 if curiosity were always     
excited for   worthy objects40--,m4 ,,de
 ,r,,aumur4     ,,preface4   ,the reader
 is entitled to know the origin of the  
small work which he holds in his hands4 
,in ,august #aheb1 being about to write 
a short article on ,locks for a         
,cyclopdia of ,useful ,arts1 of which ,i
 am the editor1 ,i consulted my esteemed
 and lamented friend1 the late          
,professor ,cowper1 of ,king's ,college1
 as to the desirability of explaining to
 the general reader the defects of some 

of our ,english locks1 which1 previous  
to the celebrated 8lock controversy0 of 
#ahea1 had borne a high character for   
skilful construction1 beauty of         
workmanship1 and undoubted security4    
,professor ,cowper expressed his strong 
conviction that by exposing the defects 
of our locks1 the cause of mechanical   
science1 as well as the public in       
general1 would be benefited2 that if our
 locks were defective1 inventors would  
be stimulated to supply the defects1 and
 the art of the locksmith would be      
raised accordingly4 ,he considered that 
,mr4 ,hobbs had made a considerable step
 in advance in the constructive details 
of his art1 not only in having detected 
the weak points of some of our best     
,english locks1 but also in having      
introduced two or three new locks1 which
 appeared to be more secure than any of 
those previously produced4 ,professor   
,cowper gave me an introduction to ,mr4 
,hobbs1 who placed at my disposal a     
variety of literary materials relating  

to the history and construction of      
locks1 and stated his intention at some 
future time of bringing out a small book
 on the subject1 if he could meet with a
 publisher4 ,i recommended him to offer 
the work to ,mr4 ,weale1 for insertion  
in his series of ,rudimentary ,works4   
,this was accordingly done1 and ,i was  
invited to prepare the work2 but as my  
engagements did not leave me sufficient 
leisure to write the book1 ,i requested 
my friend ,mr4 ,george ,dodd to put the 
materials together1 and to search for   
more4 ,mr4 ,dodd acceded to my request2 
and having completed his part of the    
work1 ,i subjected it to a careful      
revision1 and added various details     
which seemed to be necessary to         
completeness1 at least so far as the    
narrow limits of a small rudimentary    
work would admit of completeness4 ,the  
manuscript was then sent to press3 each 
sheet as it was received from the       
printer was submitted to ,mr4 ,hobbs1   
who read it with care1 and made his     

annotations and corrections thereon4    
,mr4 ,hobbs and ,i then had a meeting1  
when the additions and corrections were 
read and discussed1 and admitted or     
rejected as the case might be4 ,the     
sheet having been thus corrected was    
sent to press4  ,it should also be      
stated that1 during the progress of the 
work1 ,mr4 ,weale1 at my request1 wrote 
to ,messrs4 ,bramah1 and also to        
,messrs4 ,chubb1 informing them that a  
,rudimentary ,treatise on the           
,construction of ,locks was being       
prepared1 and requesting them to state  
in writing what alterations or          
improvements they had made in their     
locks since the date of the ,great      
,exhibition4 ,the communications which  
we have received from these celebrated  
firms are inserted verbatim1 in their   
proper places1 in the present work4     
,such is the mode in which this small   
volume has been prepared4 ,i have       
endeavoured to perform an editor's duty 
conscientiously1 without entertaining   

the feeling of a partisan in the matter4
 ,my chief object in superintending the 
production of this book 7an object in   
which the ,publisher fully participates7
 is to advance the cause of mechanical  
science1 and to supply a deficiency in  
one of the most interesting portions of 
its ,english literature4    ,c4         
,,tomlinson4    ,bedford ,place1        
,ampthill ,square1   ,july #ahec4       
,,advertisement4   ,the first edition of
 this volume1 though at the date of its 
appearance co-ordinating with the state 
of knowledge of the period1 and         
containing matter well arranged and     
lucidly described--as must have been    
expected from the reputation of its     
author--had1 through the lapse of the   
few intervening years1 inevitably become
 somewhat behind the state of the art of
 which it treats--one which is daily    
receiving the attentive consideration of
 many skilful men1 and occasional marked
 improvements4 ,amongst those of later  
years none are more noteworthy than the 

locks patented by ,mr4 ,fenby1 of       
,birmingham2 of these an account1 with  
accurate illustrations1 for which the   
drawings are supplied by the inventor1  
is now added1--together with a brief    
essay upon the important but popularly  
ill-understood subject of iron safes4   
,,robert ,,mallet4    ,april1 #ahfh4    
,in reference to ,mr4 ,smyth's letter1  
which is given at pp4 #acj1 #aca1 that  
gentleman is desirous to state that it  
was in consequence of the defects there 
pointed out that ,mr4 ,hobbs was enabled
 to pick the ,bramah lock operated upon1
 which had been manufactured forty years
 previously1 when the sliders were made 
of iron instead of steel as they now    
are1 and yet1 notwithstanding that and  
the other defects pointed out1 it took  
,mr4 ,hobbs sixteen days to pick it4 ,in
 proof of the security of the ,bramah   
lock1 ,mr4 ,smyth mentions that ,mr4    
,hobbs's best workman failed in picking 
an ordinary #c-;inch ,bramah box lock2  
and that a person in the employ of      

,messrs4 ,johnson and ,ravey1 of        
,conduit ,street1 failed also in his    
attempt to pick a #f-;inch cellar-door  
lock1 though he had the lock in his     
possession for twelve months1 employing 
his evenings in making instruments and  
trying to pick it4 ,mr4 ,smyth          
contradicts the statement made at page  
#abh1 that the new lock was removed from
 the window through any fear of its     
being opened4 ,on the contrary1 it was  
put up especially to afford an          
opportunity for ,mr4 ,hobbs to make1 if 
he thought fit1 another trial1 and it   
remained in the window four months4 ,the
 sole cause of its removal was to stop  
the impertinent applications of men and 
boys1 which interfered too much with the
 general business of the firm4          
,,contents4     ,,chap4                 
,,page       ,i4 ,on ,locks and         
,lock-literature                        
#a      ,,ii4 ,ancient ,locks3 ,grecian1
 ,roman1 ,egyptian                      
#h     ,,iii4 ,lock classification4 ,the

 ,puzzle-,lock and the ,dial-,lock      
#af      ,,iv4 ,warded ,locks1 with     
their varied appendages                 
#bg       ,v4 ,on ,tumbler or ,lever    
,locks                                  
#dc      ,,vi4 ,the ,bramah ,lock       
#fd     ,,vii4 ,american ,locks         
#hb    ,,viii4 ,the ,lock ,controversy3 
previous to the date of the ,great      
,exhibition                             
#ajb      ,,ix4 ,the ,lock ,controversy3
 during and since the time of the       
,great ,exhibition                      
#aae       ,x4 ,effects of the ,great   
,exhibition of #ahea in improving       
,english ,locks                         
#adj      ,,xi4 ,the ,lock and ,key     
,manufacture                            
#aed     ,,xii4 ,english ,patents for   
,locks4 ,aubin's ,lock ,trophy4         
,conclusion   #afd    ,,appendix4       
,,xiii4 ,on an ,improved ,construction  
of ,lock and ,key3 ,fenby's ,adytic     
,lock                                   
#agf     ,,xiv4 ,fenby's ,stop ,lock    

#aic      ,,xv4 ,note upon ,iron ,safes 
#bja       ,,on ,,the   ,,construction  
,,of ,,locks4     ,,chapter ,i4  ,,on   
,,locks ,,and ,,lock-,,literature4      
,the manufacture of locks1 and a        
consideration of the mechanical         
principles involved in their            
construction and security1 have never   
yet been treated with any degree of     
fulness in an ,english work4            
,lock-making has occupied a large amount
 of ingenuity1 and lock-patents have    
been obtained in considerable number1   
though not always1 we are satisfied1    
with a commensurate return for the      
expense incurred1--but lock-philosophy  
7if so it may be designated7 has not    
been largely attended to4  ,and yet it  
may safely be said that much which is   
both mechanically and commercially      
important is comprised in a lock4 ,every
 improvement in the manufacture of iron1
 steel1 and brass--that is1 in the      
tool-making and machine-making          
processes--may be made to reflect its   

light on the lock-manufacture2 the      
stamping1 the casting1 the planing1 the 
slotting1 the screw-cutting1 the        
polishing of metals1--all1 in proportion
 as they are improved1 impart some of   
their aid to the lock-maker4 ,then1 in  
the finer kinds of locks1 the works are 
so delicate as to approach to the nicety
 of clockwork2 thereby combining the    
manipulative skill of a talented artisan
 with the rougher mechanical work of the
 smith4 ,the principles of mechanical   
science are also appreciated by many    
lock-makers4 ,the lever1 the inclined   
plane1 the eccentric1 the cam1 the      
screw1 the wheel and pinion1 the        
ratchet1 the spring1--all are brought to
 bear on the internal mechanism of      
locks1 frequently in many novel         
combinations4  ,the commercial          
importance of locks--though of course   
never seriously questioned when once    
fairly brought before one's             
attention--has been recently rendered so
 apparent as to have risen to the       

position of a public topic4 ,if a strong
 room1 containing gold and silver1 notes
 and bills1 books and papers--if such a 
room be necessarily shielded from       
intrusion1 it becomes no less necessary 
that the shield should be really worthy 
of its name1 trusty and reliable3 a good
 lock is here nearly as indispensable as
 a faithful cashier4 ,and without       
dwelling on such an auriferous picture  
as a room fall of gold1 we shall find   
ample proof of the commercial importance
 of lock-making in the ordinary         
circumstances by which we are every day 
surrounded4 ,until the world becomes an 
honest world1 or until the honest people
 bear a larger ratio than at present to 
the dishonest1 the whole of our movables
 are1 more or less1 at the mercy of our 
neighbours4 ,houses1 rooms1 vaults1     
cellars1 cabinets1 cupboards1 caskets1  
desks1 chests1 boxes1 caddies1--all1    
with the contents of each1 ring the     
changes between meum and tuum pretty    
much according to the security of the   

locks by which they are guarded4  ,a    
commercial1 and in some respects a      
social1 doubt has been started within   
the last year or two1 whether or not it 
is right to discuss so openly the       
security or insecurity of locks4 ,many  
well-meaning persons suppose that the   
discussion respecting the means for     
baffling the supposed safety of locks   
offers a premium for dishonesty1 by     
shewing others how to be dishonest4     
,this is a fallacy4 ,rogues are very    
keen in their profession1 and know      
already much more than we can teach them
 respecting their several kinds of      
roguery4 ,rogues knew a good deal about 
lock-picking long before locksmiths     
discussed it among themselves1 as they  
have lately done4 ,if a lock--let it    
have been made in whatever country1 or  
by whatever maker--is not so inviolable 
as it has hitherto been deemed to be1   
surely it is to the interest of honest  
persons to know this fact1 because the  
dishonest are tolerably certain to be   

the first to apply the knowledge        
practically2 and the spread of the      
knowledge is necessary to give fair play
 to those who might suffer by ignorance4
 ,it cannot be too earnestly urged1 that
 an acquaintance with real facts will1  
in the end1 be better for all parties4  
,some time ago1 when the reading public 
was alarmed at being told how ,london   
milk is adulterated1 timid persons      
deprecated the exposure1 on the plea    
that it would give instructions in the  
art of adulterating milk2 a vain        
fear--milkmen knew all about it before1 
whether they practised it or not2 and   
the exposure only taught purchasers the 
necessity of a little scrutiny and      
caution1 leaving them to obey this      
necessity or not1 as they pleased4 ,so  
likewise in respect to bread1 sugar1    
coffee1 tea1 wine1 beer1 spirits1       
vinegar1 cheap silks1 cheap             
woollens--all such articles as are      
susceptible of debasement by admixture  
with cheaper substances--much more good 

than harm is effected by stating        
candidly and scientifically the various 
methods by which such debasement has    
been1 or can be produced4 ,the          
unscrupulous have the command of much of
 this kind of knowledge without our aid2
 and there is moral and commercial      
justice in placing on their guard those 
who might possibly suffer therefrom4 ,we
 employ these stray expressions         
concerning adulteration1 debasement1    
roguery1 and so forth1 simply as a mode 
of illustrating a principle--the        
advantage of publicity4 ,in respect to  
lock-making1 there can scarcely be such 
a thing as dishonesty of intention3 the 
inventor produces a lock which he       
honestly thinks will possess such and   
such qualities2 and he declares his     
belief to the world4 ,if others differ  
from him in opinion concerning those    
qualities1 it is open to them to say so2
 and the discussion1 truthfully         
conducted1 must lead to public          
advantage3 the discussion stimulates    

curiosity1 and the curiosity stimulates 
invention4 ,nothing but a partial and   
limited view of the question could lead 
to the opinion that harm can result3 if 
there be harm1 it will be much more than
 counterbalanced by good4  ,the         
literature of lock-making is1 as we have
 implied1 very scanty1 both in ,england 
and ,america4 ,the ,french and ,germans1
 though far below our level as          
lock-makers1 are very superior to us in 
their descriptions of the construction  
and manufacture of locks4 ,take1 for    
instance1 the ,french treatise published
 more than eighty years ago by the      
,acadmie des ,sciences1 and forming part
 of a folio series of manufacturing     
treatises1 illustrated very fully by    
engravings4 ,it is worth while to       
examine this work1 to see how minutely  
and faithfully the writers of such      
treatises performed their task nearly a 
century ago4 ,the ,art du ,serrurier1   
with the distinguished name of ,m4      
,duhamel du ,monceau as the author or   

editor1 was published in #agfg4 ,it     
occupies #bij folio pages1 and is       
illustrated by #db folio plates4 ,the   
first chapter gives us an introduction  
and general principles1 in which the    
choice and manipulation of materials are
 touched upon2 the different qualities  
of iron and steel2 and the processes of 
forging1 founding1 welding1 stamping1   
filing1 polishing1 c4 ,in the           
copper-plates representing these smiths'
 operations and the tools employed1#a   
there is a smithy1 with about a dozen   
smiths engaged in all these various     
occupations1 with stockings down1 and a 
due amount of workshop slovenliness4    
,the next chapter takes us into what may
 perhaps be called 8smith's work in     
general10 or at least it treats of the  
manufacture of various kinds of         
ironmongery for doors1 windows1 and     
house-fittings generally4 ,then the     
third chapter treats of 8smith's work   
which serves for the security of        
houses10 consisting of railings1        

palings1 bars1 and gates of various     
kinds--such at least as are made of     
iron4 ,in chapter four we have a notice 
of such kinds of smith's work as relate 
to the fastenings for doors1 windows1   
closets1 chests1 c42 such as hinges1    
hasps1 latches1 bolts1 and other        
contrivances less complex than an actual
 lock4 ,this brings us1 by a natural    
transition1 to locks in general1 which  
form the subject of chapter five1 to    
which is attached the illustrious name  
of ,m4 de ,raumur as the author4 ,here  
are given a hundred folio pages of      
description1 illustrated by twenty folio
 plates relating to locks1 lock-making1 
and locksmiths4 ,the sixth chapter      
relates to the iron-work of carriages1  
or the labours of the coachsmiths2 while
 chapter seven1 to wind up the work1    
relates to bell-hanging4    #a ,it is   
worthy of remark1 that the tools        
described are the same as   those which 
are used by the locksmith at the present
 day2 shewing how   little improvement  

has been made in the means of producing 
locks4  ,that chapter of the work which 
has reference to locks is the only one  
with which we have to do here4 ,it is   
arranged in a systematic manner1        
beginning with the simpler locks1       
without wards or tumblers1 and          
proceeding thence to others of more     
complex construction4 ,the period at    
which the work was written was too early
 to lead us to expect to find a         
tumbler-lock described and delineated3  
there are1 however1 numerous examples of
 single tumbler-locks1 many of them of  
great ingenuity4 ,the use of multiple   
bolts1 that is1 of many bolts shot at   
once by one action of the key1 seems to 
have been familiar enough to the        
locksmiths of those days4 ,one lock     
represented is remarkable2 it is        
attached to a strong and ponderous      
coffer or chest4 ,the chest is open2 and
 the whole under or inner surface of the
 cover is seen to be occupied by a lock 
of intricate construction2 there are no 

less than twelve bolts1 three on each   
long side1 one on each short side1 and  
one in each corner2 these bolts are so  
placed as to catch under a projecting   
rim fixed round the top of the coffer4  
,the collection of keys1 exhibited on a 
separate plate1 is remarkable for the   
great variety of forms given to them4   
,we shall by and by copy some of the    
drawings of this curious work4  ,it was 
to be expected that in the ,encyclopdie 
,mthodique1 published in the same       
country and in the same century1 the    
locksmith's art would be treated at some
 such length as in the work just        
described4 ,among the two hundred       
volumes of which the ,cyclopdie         
consists1 several are devoted to arts   
and manufactures2 and one of them       
contains the article in question4 ,it   
occupies #afh quarto pages1 and is      
illustrated by #ce copper-plate         
engravings1 shewing in detail not only  
the parts of various locks1 but the     
tools used by the lockmaker4 ,it is     

proper1 however1 to remark1 that much of
 the letterpress and many of the plates 
relate to smith's work generally1 and   
not exclusively to lock-work2 the       
,french name serrurerie being applied   
not only to lock-making1 but to most of 
the smith's work required in            
dwelling-houses4 ,this affords1 indeed1 
a striking illustration of the fact1    
that until lately a lock-maker has been 
regarded rather as a smith than as a    
machinist1 rather as a forger and filer 
of pieces of iron1 than as a fabricator 
of delicate mechanism4 ,one of the most 
curious features in this treatise is a  
vocabulary1 containing1 in alphabetical 
arrangement1 a minute account of all the
 ,french technical terms employed in the
 locksmith's art4 ,this vocabulary alone
 occupies #ch quarto pages4  ,the       
,germans1 like the ,french1 bestow great
 attention on their treatises relating  
to the manufacturing arts4 ,some of     
these are1 indeed1 worked up to a degree
 of minuteness which would seem         

superfluous1 where little distinction is
 drawn between the importance of        
fundamental principles and that of mere 
technical details4 ,locks have had their
 due share4 ,the article on locks in    
,prechtl's ,technological ,encyclopdia  
written by ,karmarsch1 and published in 
#ahdb1 occupies about #adj pages4 ,locks
 are very minutely classified by the    
author1 according to their purposes and 
their modes of action1 and are          
illustrated by many plates4 ,one of his 
classifications is into ,german1        
,french1 and ,bastard locks1 referring  
in part to the extent to which the key  
turns round in the lock2 and the last of
 the three having an intermediate       
character between the other two4 ,after 
treating of the ordinary warded locks1  
he comes to the combination principle2  
and it is profitable here to notice1 how
 well the works of our machinists are   
understood on the continent1 when they  
have any thing to recommend them2 there 
are a dozen closely printed pages       

devoted to a minute description of      
,bramah's invention1 with all the       
separate parts illustrated by           
copper-plate engravings4 ,after this    
comes a more general account of the     
details and manufacture of locks1       
similarly illustrated by engravings4    
,whatever may be the merits of the      
different articles relating to locks in 
the various ,english cyclopdias1 there  
are none approaching in length to the   
article in ,prechtl's work4 ,but when we
 consider that ,prechtl devotes twenty  
large volumes to technological or       
manufacturing subjects1 he is of course 
able to devote a larger space to each   
article than is given in ,english works4
 ,both in ,england and in ,america1 men 
are more disposed to do the work than to
 describe it when done4 ,in the         
,encyclopdia ,britannica1 in ,rees'     
,cyclopdia1 in ,hebert's ,engineers' and
 ,mechanics' ,cyclopdia1 in the         
,encyclopdia ,metropolitana1 in the     
,penny ,cyclopdia1 and in other similar 

works1 locks are described as well as   
can be expected within the limits       
assigned to the articles4 ,mr4 ,bramah's
 essay on locks1 and on his own lock in 
particular1 is one of the few ,english  
pamphlets devoted expressly to this     
subject4 ,an excerpt from the           
proceedings of the ,institute of ,civil 
,engineers1 in #ahea1 gives an          
interesting paper on locks by ,mr4      
,chubb2 and shorter reports of papers   
and lectures have been published in     
various ways4 ,perhaps the best account 
of locks which we have1 considering the 
limited space within which a great deal 
of information is given in a very clear 
style1 is that contained in ,mr4        
,tomlinson's ,cyclopdia of ,useful      
,arts4     ,,chapter ,,ii4  ,,ancient   
,,locks3 ,,grecian1 ,,roman1 ,,egyptian4
   ,locks and door-fastenings have not1 
until modern times1 been susceptible of 
any classified arrangement according to 
their principles of construction4 ,they 
have been too simple to require it1 and 

too little varied to permit it4 ,that   
some such fastenings must be employed   
wherever doors of any kind are used is  
sufficiently apparent2 and there is a   
little 7though only a little7           
information obtainable1 which shews the 
nature of the fastenings adopted in     
early times4 ,the bolt1 the hasp1 the   
chain1 the bar1 the latch1 the lock1 all
 were known1 in one or other of their   
various forms1 in those ages which we   
are accustomed to consider classical4   
,travellers1 generally speaking1 do not 
descend to locks1 or rather they do not 
think about them2 otherwise they might  
have collected much that would have been
 novel and applicable to the present    
work2 and1 indeed1 there is some ground 
for the assertion1 that a notice of the 
door-fastenings of all nations would    
reveal to us something of the social and
 domestic habits of various members of  
the great human family4 ,be this as it  
may1 however1 we may profitably make a  
little inquiry into the locks of ancient

 times4  ,in the volumes of ,lardner's  
,cyclopdia relating to the 8,manners and
 ,customs of the ancient ,greeks and    
,romans10 we do not find any mention of 
the kinds of locks used by those        
nations2 but the author1 while          
describing the houses1 says3--8,doors   
turned anciently upon large pivots in   
the centre1 let into sockets in the     
lintel and threshold1 so that one of the
 sides opened inwards1 the other        
outwards2 and ,plutarch gives the       
following curious reason why persons    
were to knock and alarm the porter1 viz4
 lest the visitor entering unawares     
should surprise the mistress or daughter
 of the family busy or undressed1 or    
servants under correction1 or the maids 
quarreling40 ,as the visitors had thus  
the power 7if permitted so to do7 to    
open the outer door of a house1 it would
 appear that very little in the nature  
of a lock was employed under ordinary   
circumstances1 unless indeed it were a  
mere latch4 ,in respect to ,roman houses

 it is stated1 that 8the doors revolved 
upon pivots1 which worked in a socket   
below1 and were fastened by bolts which 
hung from chains40 ,there is no mention 
of locks here4 ,mr4 ,st4 ,john1 in his  
work on the same subject1 says3 8,the   
street-door of a ,grecian house1        
usually1 when single1 opened outwards2  
but when there were folding-doors they  
opened inwards1 as with us4 ,in the     
former case it was customary1 when any  
one happened to be going forth1 to      
knock1 or call1 or ring a bell1 in order
 to warn passengers to make way40 ,after
 describing the various kinds of wood of
 which the doors were made1 he proceeds3
 8,the doors at first were fastened by  
long bars passing into the wall on both 
sides2 and by degrees smaller bolts1    
hasps1 latches1 and locks and keys1     
succeeded4 ,for example1 the outer door 
of the thalamos in ,homer was secured by
 a silver hasp1 and a leathern thong    
passed round the handle1 and tied1      
perhaps1 in a curious knot40  ,mr4      

,yates1 in a learned article on this    
subject in ,smith's ,dictionary of      
,greek and ,roman ,antiquities1 collects
 numerous details scattered through     
various early writers4 ,we will string  
together a few of these details1 so far 
as they have any relation to the        
fastenings of doors4 ,the outer door of 
a ,roman house was generally called     
janua2 whereas the inner doors were     
called ostia4 ,the doorway1 when        
complete1 consisted of four             
indispensable parts--the threshold or   
sill1 the lintel1 and the two jambs4    
,the threshold1 on which the feet trod1 
was often regarded with a kind of       
superstitious reverence2 the lintel1    
which crossed the doorway at the top1   
having a considerable superincumbent    
weight to bear1 was usually made of one 
piece of timber or stone of great       
strength2 the jambs1 or side uprights1  
were also made in one piece each4 ,the  
doorway1 in every building of the least 
importance1 contained two doors folding 

together2 even the internal doors had   
their bivalve construction4 ,but in     
every case each of the two valves was   
wide enough to allow persons to pass    
through without opening the other2 in   
some cases even each valve was double1  
so as to fold like our window-shutters4 
,these doors1 or valves1 were not hinged
 to the side-posts1 as with us1 but     
were1 as has already been stated1       
pivoted to the lintel above and the     
threshold below4 ,the fastening usually 
consisted of a bolt placed at the base  
of each valve or half-door1 so as to    
admit of being pushed into a socket made
 in the sill to receive it4 ,the        
doorways in some of the houses at       
,pompeii still shew two holes in the    
sill1 corresponding to the bolts in the 
two valves4 ,at night1 the front door of
 the house was further secured by means 
of a wooden and sometimes an iron bar   
placed across it1 and inserted into     
sockets on each side of the doorway2    
hence it was necessary to remove the bar

 in order to open the door4             
,chamber-doors were often secured in the
 same manner4 ,in the ,odyssey there is 
mention of a contrivance 7adverted to by
 ,mr4 ,st4 ,john7 for bolting or        
unbolting a door from the outside2 it   
consisted of a leather thong inserted   
through a hole in the door1 and by means
 of a loop1 ring1 or hook1 capable of   
taking hold of the bolt so as to move it
 in the manner required4 ,we have here  
evidently the elements of a more        
complete mechanism2 for the bolt was a  
rude lock in the same degree that the   
thong was a rude key4 ,that the ,romans 
afterwards had real locks and keys is   
clear2 for the keys found at            
,herculaneum and ,pompeii1 and those    
attached to rings1 prove that a kind of 
warded lock must have been well known4#b
 ,there are the remains of a tomb at    
,pompeii1 the door of which is made of a
 single piece of marble1 including the  
pivots1 which were encased in bronze1   
and turned in sockets of the same metal2

 it is three feet high1 two feet nine   
inches wide1 and four and a quarter     
inches thick2 it is cut in front to     
resemble panels1 and thus approaches    
nearer in appearance to a modern wooden 
door2 and it was fastened by some kind  
of lock1 traces of which still remain4  
#b ,an examination of the ,roman keys in
 the ,british ,museum   sufficiently    
attests this fact4  ,the same facts     
frequently become more clear when       
described in different words by         
different writers4 ,we shall make use of
 this circumstance4 ,mr4 ,donaldson1 in 
his ,essay on ,ancient ,doorways1       
presents us with details which          
illustrate many of the foregoing        
remarks4 8,homer describes the treasures
 and other valuable objects 7mentioned  
in the ,odyssey7 as being kept in the   
citadel1 secured merely by a cord       
intricately knotted4 ,this1 of course1  
was soon found to be a very insufficient
 protection1 and therefore a wooden bar 
was adopted inside the doors of houses1 

to which it was attached by an iron     
latch1 fastened or removed by a key     
adapted to it2 this key was easily      
applied from within2 but in order to get
 at it from without1 a large hole was   
made in the door1 allowing the          
introduction of the hand1 so as to reach
 the latch and apply the key4 ,the lock 
called the ,lacedmonian1 much celebrated
 by ancient writers1 was invented       
subsequently2 it was especially fitted  
for the inner chambers of houses1 the   
bar fastenings continuing to be employed
 for closing the outer doors of         
dwellings and the entrance-gates to     
cities4 ,the ,lacedmonian lock did not  
require a hole to be made in the door1  
for it consisted of a bolt placed on    
that side of the entrance-door which    
opened1 and on the inside of a          
chamber-door4 ,when a person who was    
outside wished to enter1 it was         
necessary for him to insert the key in a
 little hole and to raise the bolt2 and 
in time this species of fastening was   

improved by the insertion of the bolt in
 an iron frame or rim permanently       
attached to the door by a chain1 and    
fastening the door by the insertion of  
the hasp1 through the eye of which was  
forced the bolt inside the lock by      
applying the key40 ,after quoting a     
,latin sentence from ,varro in          
elucidation of his subject1 ,mr4        
,donaldson proceeds to observe1 that for
 the most part the locks of the ancients
 were different in principle from those 
of modern days1 not being inserted or   
mortised into the doors1 nor even       
attached except by a chain2 they were1  
in fact1 padlocks4  ,one of the passages
 in the ,odyssey alluding to the        
primitive mode of fastening the valves  
or folding-doors of a house runs thus3--
    8,whilst to his couch himself the   
prince addressed1    ,the duteous nurse 
received the purple vest3    ,the purple
 vest with decent care disposed1    ,the
 silver ring she pulled1 the door       
reclosed2    ,the bolt1 obedient to the 

silken cord1    ,to the strong staple's 
inmost depth restored1    ,secured the  
valves40  ,most of the other great      
nations of antiquity resembled either   
the ,egyptians or the ,greeks and       
,romans1 more or less closely1 in their 
domestic and domiciliary arrangements2  
or1 at any rate1 so far as such humble  
matters as locks and keys are concerned1
 we need not seek far from those nations
 for examples4 ,the ,nineveh and other  
,assyrian explorations have1 however1   
revealed many curious and unexpected    
facts2 from the temples and the palaces 
we may by and by penetrate into the     
houses and rooms of the citizens        
sufficiently to know how their doors    
were fastened4 ,in the mean time ancient
 ,egypt awaits our notice4  ,sir ,j4    
,gardner ,wilkinson1 in his ,manners and
 ,customs of the ,ancient ,egyptians1   
gives the following information         
concerning the doors and door-fastenings
 of that remarkable people1 on the      
authority of models1 sculptures1 and    

paintings1 still existing4 ,the doors   
were frequently stained so as to imitate
 foreign and rare woods4 ,they were     
either of one or two valves1 turning on 
pieces of metal1 and were secured within
 by a bar or by bolts4 ,some of these   
bronze pins have been discovered in the 
tombs of ,thebes2 they were fastened to 
the wood with nails of the same metal1  
the round heads of which served also as 
ornaments4 ,in the stone lintels and    
floors behind the thresholds of the     
tombs and temples are still frequently  
to be seen the holes in which the       
pivot-pins turned1 as well as those of  
the bolts and bars1 and the recess for  
receiving the opened valves4 ,the       
folding-doors had bolts in the centre1  
sometimes above as well as below2 a bar 
was placed across from one wall to the  
other4  ,in many of the ancient         
,egyptian doors there were wooden locks 
fixed so as to fasten across the centre 
at the junction where the two folds of  
the door met4 ,it is difficult1 by mere 

inspection of the bas-reliefs and       
paintings1 to decide whether these locks
 were opened by a key1 or were merely   
drawn backwards and forwards like a     
bolt2 but if they were really locks1 it 
is probable that they were on the same  
principle as the ,egyptian lock still in
 use4 ,for greater security1 these      
modern locks are occasionally sealed    
with a mass of clay2 and there is       
satisfactory evidence that the same     
custom was frequently observed among the
 ancient inhabitants of that country4   
,sir ,j4 ,g4 ,wilkinson gives a         
representation of an iron key1 now in   
his possession1 which he procured among 
the tombs at ,thebes1 and which looks   
very much like a modern burglar's       
picklock4 ,in relation to keys          
generally1 and after mentioning the use 
of bronze for their manufacture1 he     
says3 8,at a later period1 when iron    
came into general use1 keys were made of
 that metal1 and consisted of a straight
 shank about five inches in length1 and 

a bar at right angles with it1 on which 
were three or more projecting teeth4    
,the ring at the upper extremity was    
intended for the same purpose as that of
 our modern keys2 but we are ignorant of
 the exact time when they were brought  
into use2 and the first invention of    
locks distinct from both is equally     
uncertain2 nor do ,i know of any        
positive mention of a key1 which1 like  
our own1 could be taken out of the lock1
 previous to the year #accf before our  
era2 and this is stated to have been    
used to fasten the door of the summer   
parlour of ,eglon1 the king of ,moab4   
,the description here adverted to is    
that contained in ,judges iii4 #bc-be3  
#8,ehud went forth through the porch1   
and shut the doors of the parlour upon  
him1 and locked them 444 his servants   
444 took a key1 and opened them4'0  ,the
 curious and ingenious wooden lock of   
ancient ,egypt is still in use in ,egypt
 and ,turkey4 ,in ,eton's ,survey of the
 ,turkish ,empire1 published towards the

 close of the last century1 the locks   
then and there in use are thus          
described3 8,nothing can be more clumsy 
than the door-locks in ,turkey2 but     
their mechanism to prevent picking is   
admirable4 ,it is a curious thing to see
 wooden locks upon iron doors1          
particularly in ,asia1 and on their     
caravanserais and other great buildings1
 as well as upon house-doors4 ,the key  
goes into the back part of the bolt1 and
 is composed of a square stick with five
 or six iron or wooden pins1 about half 
an inch long1 towards the end of it1    
placed at irregular distances1 and      
answering to holes in the upper part of 
the bolt1 which is pierced with a square
 hole to receive the key4 ,the key being
 put in as far as it will go1 is then   
lifted up2 and the pins1 entering the   
corresponding holes1 raise other pins   
which had dropped into these holes from 
the part of the lock immediately above1 
and which have heads to prevent them    
falling lower than is necessary4 ,the   

bolt1 being thus freed from the upper   
pins1 is drawn back by means of the key2
 the key is then lowered1 and may be    
drawn out of the bolt4 ,to lock it      
again1 the bolt is only pushed in1 and  
the upper pins fall into the holes in   
the bolt by their own weight40 ,mr4     
,eton1 probably seeing how well the     
tumbler-principle is here understood1   
says3 8,this idea might be improved on2 
but the ,turks never think of           
improving40 ,the locks on the doors of  
modern houses in ,cairo seem to be of   
this long-established form1 except where
 iron locks have been imported from     
,europe4  ,a letter was inserted in the 
,journal of ,design for ,july #ahej from
 ,mr4 ,w4 ,c4 ,trevelyan2 in which1     
after adverting to the ,egyptian lock1  
he says3 8,it is remarkable that the    
locks which have been in use in the     
,fare ,islands1 probably for centuries1 
are identical in their construction with
 the ,egyptian4 ,they are1 lock and key1
 in all their parts made of wood2 of    

which material1 if ,i mistake not1 they 
have also been found in ,egyptian       
catacombs2 and so identical with the    
,farese in structure and appearance1    
that it would not be easy to distinguish
 one from the other40  ,illustration3   
fig4 #a4  ,illustration3 fig4 #b4       
,illustration3 fig4 #c4  ,illustration3 
fig4 #d4  ,the construction of this     
remarkable ,egyptian or pin-lock will be
 understood from the accompanying       
engravings4 ,the quadrangular portion1 a
 a fig4 #a1 is the case of the lock1    
screwed or otherwise fastened to the    
door1 having a wooden bolt1 b b1 passing
 horizontally through a cavity in it4   
,in the part of the case above the bolt 
are several small cells containing      
headed pins1 arranged in any desired    
form2 and in the top of the bolt itself 
are an equal number of holes similarly  
arranged4 ,the effect of this           
arrangement is such that1 when brought  
into the right positions1 the lower ends
 of the headed pins drop into the       

corresponding holes in the bolt1 thereby
 fastening the bolt in the lock-case4 ,a
 large hollow1 or cavity1 is made at the
 exposed end of the bolt1 the cavity    
extending as far as and beyond the holes
 occupied by the pins4 ,the key consists
 of a piece of wood 7shewn in two       
positions1 figs4 #c and #d17 having pins
 arranged like those in the lock1 and   
projecting upwards just to a sufficient 
distance to reach the upper surface of  
the bolt4 ,this being the arrangement1  
whenever the key is introduced and      
pressed upwards1 its pins exactly fill  
the holes in the bolt1 and by so doing  
dislodge those which had fallen from the
 upper part of the case4 ,the bolt may1 
under these circumstances1 be withdrawn 
7as shewn in fig4 #b71 leaving the      
headed pins elevated in their cells1    
instead of occupying the position shewn 
by the dotted lines in fig4 #a4 ,the    
cavity in the bolt must of course be    
high enough to receive the thickness of 
the key1 and also the length of the pins

 protruding from the key4  ,this        
primitive lock comprises many of the    
best features of the tumbler or         
lever-locks of later days1 as will be   
seen in a future chapter4 ,there will   
also be opportunities of shewing how the
 pin-action has been applied in other   
ways in some of the modern locks4       
,,chapter ,,iii4  ,,lock                
,,classification4 ,,the ,,puzzle-,,lock 
,,and ,,the ,,dial-,,lock4   ,in        
approaching the subject of modern locks 
it becomes necessary to decide upon some
 method of treating the widely-scattered
 and diverse materials which are        
presented to our notice4 ,one plan would
 be to trace the subject                
chronologically1 by describing1 in the  
order of their invention1 the most      
important locks which have been         
presented to public notice4 ,but this   
would be attended with some             
disadvantages3 the peculiar characters  
of the several locks would not be       
brought out with sufficient             

distinctness2 and the result1 so far as 
the reader is concerned1 would rather   
tend to confusion than to a clear       
appreciation of the subject4 ,there are 
more advantages belonging to a          
classification of locks under certain   
headings1 according to some marked      
peculiarities in their modes of action4 
,this is a convenient plan1 but it is   
not an easy one to put in execution2 for
 inventors have not sought to place     
their locks in any particular class1 but
 rather to call attention to their      
merits4 ,moreover1 many locks embody two
 or three distinct principles so        
equally1 that it will often be difficult
 to decide in which class to place them4
 ,this1 nevertheless1 may be done with  
an approach to correctness4 ,it is      
necessary first1 however1 to explain    
certain technical terms by which locks  
are distinguished one from another4     
,locks1 in truth1 admit of an immense   
variety1 which1 however important to be 
known to locksmiths1 carpenters1 and    

others employed on them1 need only be   
glanced at very cursorily by the general
 reader4 ,some locks are named according
 to the purposes to which they are to be
 applied2 others according to their     
shape1 or the principles of their       
construction4 ,in the first place1 there
 is the distinction between in-door and 
out-door locks4 ,of in-door locks1 one  
principal kind is the draw-back lock1   
for street-doors1 in which the bolt is  
capable of maintaining any one of three 
positions3 it may be locked by the key1 
or left half-way out by the pressure of 
a spring1 or be drawn back by a handle4 
,in the first position1 it can only be  
withdrawn by the key2 in the second1 it 
closes the door1 but can easily be      
withdrawn by the handle2 and in the     
third1 it leaves the door unfastened4   
,if these locks are made of iron and    
carefully finished1 they are further    
called iron-rim2 but if made of wood1   
suitable for back-doors and inferior    
purposes1 they are spring-stock4 ,for   

the doors of rooms1 there are the       
iron-rim1 the brass-case1 and the       
mortise lock2 the second supplants the  
first1 and the third the second1 as we  
advance in the elegance of the          
door-fittings4 ,other designations for  
room-locks depend on the number of the  
bolts3 thus1 if there be only one bolt1 
it is a dead lock or closet lock2 if    
there be a second bolt1 urged by a      
spring and drawn back by a handle1 it is
 a two-bolt lock2 and if there be also a
 third1 a private bolt acting only on   
one side of the door1 it is a three-bolt
 lock4 ,again1 according to the kind of 
handle employed1 it may be a knob lock  
or a ring lock4 ,according to which edge
 of the door it is to be fixed1 it      
becomes a right-hand or a left-hand     
lock4 ,if the wards of the lock are of  
somewhat superior quality1 and bend     
round nearly to a circle1 the lock is   
one-ward round1 two-ward round1 and so  
forth4 ,if the lock has no wards at all1
 it is plain2 if the wards are of common

 character1 they are often called       
wheels1 and then the lock becomes       
one-wheel1 two-wheel1 c4 ,sometimes the 
lock is named from certain fancied      
resemblances in the shape of the ward1  
as the ,l-ward1 ,t-ward1 or ,z-ward4 ,if
 the wards are cast in brass1 instead of
 being made of slips of iron or copper1 
the lock is termed solid ward4  ,of the 
numerous but smaller varieties known by 
the collective name of cabinet locks1   
there are the cupboard1 the bookcase1   
the desk1 the portable desk1 the table1 
the drawer1 the box1 the caddy1 the     
chest1 the carpet-bag1 and many other   
locks4 ,all these locks are further     
called straight1 when the plate is to be
 screwed flat against the wood-work2    
cut1 when the wood is to be so cut away 
as to let in the lock flush with the    
surface2 and mortise1 when a cavity is  
excavated in the edge of the door for   
the reception of the lock4  ,out-door   
locks are usually wooden stock locks1   
for stables1 gates1 c42 comprising many 

varieties of ,banbury1 bastard1 fine1 c4
 ,there are ,d locks and ,p locks1 for  
gates1 designated from their shapes2 and
 there are the numerous kinds of        
padlocks4  ,the above terms are employed
 chiefly between the makers of the locks
 and the persons who fix them in their  
places2 but there are other terms and   
names1 more familiarly known1 which will
 come under notice in future pages4  ,it
 is scarcely worth while to descant upon
 the 8middle age0 of lock-making--to    
impart to the subject so much of dignity
 as to be susceptible of regular        
historical treatment4 ,true1 we know    
that wards were employed before tumblers
 7unless1 indeed1 the pins of the       
,egyptian lock be considered as         
tumblers--a character to which they     
present considerable claim71 and that   
wards may be taken as the representative
 of the medieval period of lock-making2 
but it may be more profitable to proceed
 in our notice of the different kinds of
 locks in an order which will in itself 

partake somewhat of the historical      
character4  ,apart from all the warded  
and tumbler locks are the very curious  
puzzle or letter-locks2 a construction  
which we propose to dismiss out of hand 
in the present chapter1 before treating 
of those which have more commercial     
importance4  ,the puzzle-lock is        
generally in the form of a padlock1     
which is opened and closed without the  
use of a key1 and which has certain     
difficulties thrown in the way of its   
being opened by any one who is not in   
the secret of the person who closed it4 
,it is1 in fact1 one of the locks in    
which the doctrine of permutation is    
made to contribute to the means of      
security4 ,the key to open it is a      
mnemonic or mental one1 instead of one  
of steel or iron4 ,two centuries ago1   
the puzzle-lock attracted far more      
attention than any other4 ,it has always
 certain movable parts1 the movement of 
which constitutes the enigma4 ,some of  
these very curious and out-of-the-way   

locks are so formed as to receive the   
name of dial-locks2 but the chief among 
them are ring-locks--a name the meaning 
of which will be presently understood4  
,the puzzle or letter-lock of the ring  
kind1 then1 consists essentially of a   
spindle2 a barrel1 encompassing the     
spindle2 two end-pieces1 to keep the    
spindle and barrel in their places2 and 
the shackle1 hinged to one of these     
end-pieces4 ,to unfasten the lock1 one  
of the end-pieces must be drawn out a   
little1 to allow the shackle or         
horse-shoe to be turned on its hinge2   
and the question arises1 therefore1 how 
this end-piece is to be acted upon4     
,this is effected in a very ingenious   
way3 there are four studs or projections
 in a row on the spindle1 and as the    
spindle fits pretty closely in the      
barrel1 the former cannot be drawn out  
of the latter unless there be a groove  
in the interior of the barrel1 as a     
counterpart to the studs on the exterior
 of the spindle2 four rings fit on the  

barrel1 on the interior of each of which
 there is a groove2 and unless all these
 four grooves coincide in direction1 and
 even lie in the same plane as the      
groove in the barrel1 the studs will not
 be able to pass1 and the spindle cannot
 be drawn out4 ,each ring may be easily 
made to work round the barrel by means  
of the fingers1 and to maintain any     
position which may be given to it4      
,there are outer rings1 one over each of
 the rings just described1 with the     
letters of the alphabet 7or a           
considerable number of them7 inscribed  
on each2 and these outer rings1 by means
 of notches on the inside1 govern the   
movements of the inner rings4  ,the     
action is1 therefore1 as follows3 when  
the padlock is to be locked1 the rings  
are so adjusted that all the grooves    
shall be in a right line2 the spindle is
 thrust in1 the end-piece is fixed on1  
and the shackle is shut down4 ,the      
padlock is now fastened2 but a reverse  
order of proceeding would as easily open

 it again1 and therefore the 8safety0 or
 8puzzle0 principle is brought into     
requisition4 ,the outer rings are moved 
with the finger1 so as to throw the     
various interior grooves out of a right 
line1 and thus prevent the withdrawal of
 the spindle4 ,as each ring may be      
turned round through a large or a small 
arc1 and all turned in different        
degrees1 the variations of relative     
position may be almost infinite4 ,the   
letters on the outer rings are to assist
 the owner to remember the particular   
combination which he had adopted in the 
act of locking2 for no other combination
 than this will suffice to open the     
lock4 ,there may1 for instance1 be the  
four letters ,l ,o ,c ,k in a line1     
which line is brought to coincide with  
two notches or marks at the ends of the 
apparatus2 and until all the four outer 
rings are again brought into such       
relative position as to place the       
letters in a line1 the lock cannot be   
opened4  ,there are many allusions to   

locks1 apparently belonging to the      
letter or puzzle principle1 in authors  
who flourished two or three centuries   
ago4 ,thus1 in ,beaumont and ,fletcher's
 play of the ,noble ,gentleman1 written 
in the early part of the seventeenth    
century1 one of the characters speaks of
    8,a cap-case for your linen and your
 plate1    ,with a strange lock that    
opens with ,a,m,e,n40  ,and in some     
verses by ,carew1 written about the same
 time1 there is an analogy drawn1 in    
which one of the things compared is--   
8,a lock   ,that goes with letters2 for 
till every one be known1   ,the lock's  
as fast as if you had found none40  ,in 
the ,memorabilia of ,vanhagen von ,ense1
 written about the middle of the        
seventeenth century1 a commendatory     
notice is given of a letter-lock1 or    
combination-lock1 invented by ,m4       
,regnier1 ,director of the ,muse        
d',artillerie at ,paris4 8,regnier10 we 
are told1 8was a man of some invention1 
and had taken out a patent for a sort of

 lock1 which made some noise at the     
time4 ,every body praised his invention1
 and bought his locks4 ,these consisted 
of broad steel rings1 four1 five1 or    
eight deep1 upon each of which the      
alphabet was engraved2 these turned     
round on a cylinder of steel1 and only  
separated when the letters forming a    
particular word were in a straight line 
with one another4 ,the word was selected
 from among a thousand1 and the choice  
was the secret of the purchaser4 ,any   
one not knowing the word might turn the 
ring round for years without succeeding 
in finding the right one4 ,the          
workmanship was excellent1 and ,regnier 
was prouder of this than of the         
invention itself4 ,the latter point     
might be contested4 ,i had a vague      
recollection of having seen something of
 the sort before2 but when ,i ventured  
to say so1 my suspicions were treated   
with scorn and indignation1 and ,i was  
not able to prove my assertion2 but many
 years afterwards1 when a book1 which as

 a boy ,i had often diligently read1    
fell into my hands1 ,regnier's lock was 
suddenly displayed4 ,the book was called
 ,silvestri a ,petrasancta ,symbola     
,heroica1 printed at ,amsterdam in      
#afhb4 ,there was an explanation at p4  
#bed1 attached to a picture2 these were 
the words3--,honorius de ,bellis1 serul 
innex orbibus volubilibus ac literatis  
circumscripsit hoc lemma--,sorte aut    
labore4#c ,however1 neither luck nor    
labour would have done much more towards
 discovering the secret of opening      
,regnier's locks1 from the variety of   
their combinations2 and their security  
seemed so great1 that the couriers'     
despatch-boxes were generally fastened  
with them40    #c 8,honorius de ,bellis 
wrote this inscription1--,by chance or  
by   labour1--round a lock composed of  
revolving rings graven with   letters40 
,this curious extract1 which was brought
 forward by ,mr4 ,chubb1 in a paper on  
locks and keys 7read before the         
,institution of ,civil ,engineers in    

#ahej71 seems to take away the credit   
from one 7,regnier7 with whose name the 
letter-lock has been most intimately    
associated4 ,we shall presently explain1
 however1 what it was that ,regnier     
effected towards perfecting the         
letter-lock4 ,in the meantime it may be 
interesting to note that the ,british   
,museum contains a copy of the work     
mentioned by ,vanhagen4 ,at the page    
indicated there is an engraving 7a      
fac-simile of which is given in fig4 #e7
 containing a drawing of a veritable    
puzzle or letter-lock2 the lock consists
 of a cylinder or barrel1 on which seven
 rings work2 each of these rings is     
inscribed with letters1 and the ends of 
the cylinder are grasped by a kind of   
shackle4  ,illustration3 fig4 #e4       
,puzzle-lock of the seventeenth century4
  ,it was a natural result of the       
arrangement of the letter-lock1 as      
invented 7conjecturally7 by ,cardan1    
that only one particular word or cipher 
or key could be used in each lock2 and  

it was to increase the puzzle-power of  
the lock that ,regnier doubled all the  
rings1 making each pair concentric1 and 
enabling the user to vary the cipher at 
pleasure4  ,the principle of the        
letter-lock1 when applied to doors1     
requires that sort of modification which
 renders it what is termed a dial-lock4 
,there are to such a lock one or more   
dials1 with a series of letters or      
figures stamped on them2 there is to    
each dial a hand or pointer connected by
 a spindle with a wheel inside the lock2
 on the wheel is a notch which has to be
 brought to a certain position before   
the bolt can be moved4 ,there are false 
notches1 to add to the difficulty of    
finding the true notch in each wheel4   
,to adjust the notches to their proper  
position1 a nut on the back of the wheel
 is loosened1 and the pointer is set at 
any letter or figure chosen by the user4
 ,the pointers and the dials perform the
 part of the outer rings1 the wheels    
that of the inner rings2 and it is easy 

to see that the same leading features   
prevail in the two kinds of lock1       
however they may differ in detail4      
,these dial-locks have not been         
numerous2 they require wheel and pinion 
work within the body of the lock1 which 
gives delicacy and complication to the  
mechanism4 ,the letter padlock1 be its  
merits great or small1 is strong and    
durable1 not liable to get out of order2
 and in so far as it requires no key or 
key-hole1 it occupies rather a special  
position among locks4 ,one of our great 
8merchant-princes0 has been a           
letter-lock inventor1 as the following  
will shew4  ,early in #aheb1 ,mr4       
,william ,brown1 the distinguished      
member for ,south ,lancashire1 read a   
paper before the ,architectural and     
,archological ,society of ,liverpool1 of
 much interest in relation to our       
present subject4 ,his object was to     
describe a letter-lock which he had     
invented1 and which had up to that time 
given high satisfaction4 ,we cannot do  

better than transcribe the paper1 as    
reported in one of the ,liverpool       
,journals1 with a few abridgments4  8,as
 your society are desirous of seeing any
 improvements or attempts at them1 ,i   
send you a stock-lock for inspection4   
,the idea for its construction ,i took  
from a letter-padlock4 ,i had a lock of 
this description made by ,mr4 ,pooley   
twenty-five years ago1 which has been in
 use ever since on ,brown1 ,shipley1 and
 ,co4's safe4444  8,its advantages ,i   
conceive to be--,first1 it cannot be    
picked1 for there is no key-hole4       
,second1 it cannot be blown up by       
gunpowder1 for the same reason4 ,third1 
you cannot drill through the door so as 
to reach the lock1 for you are          
intercepted by a steel plate on which   
your tools will not act3 thus you cannot
 introduce gunpowder that way to force  
the lock off4 ,fourth1 you cannot bounce
 off the wheels in the interior with a  
muffled hammer1 for vulcanised          
,india-rubber springs resist this4      

,fifth1 you cannot drill the spindles   
out1 as their heads are case-hardened4  
,sixth1 you cannot drive them in1 for   
they are countersunk in the door about  
half-way through4444  8,now let us set  
the lock to the word ,w ,o ,o ,d 7any   
other four letters might be used74 ,when
 you set the lock1 make a private record
 of them1 so that you may not forget    
them4 ,if parties do not know your      
letters1 nothing but violence1 applied  
by some means or other1 can enable them 
to get into your safe2 for the lock will
 not open to any thing but its talisman4
 ,take off all the large wheels and open
 the lock3 you will see that the large  
wheels have a number of false chambers2 
if you get the spurs of the bolt into   
three real chambers and one false1 you  
are as fast as ever1 for all four must  
be right4  8,having placed your key and 
pointer outside the door to point to ,w 
on brass-plate ,no4 #a1 the small wheel 
inside obeys the same impulse2 then     
maintain your small wheel steadily on   

this point1 and the large wheel ,no4 #a 
will only fit on at the right place1 the
 true opening compartment being opposite
 the spur of the bolt4 ,it being        
necessary at the time you set your lock 
that it should be open1 proceed with    
,nos4 #b and #c in the same way1 your   
pointer standing steadily at ,o4 ,no4 #d
 is the same1 the pointer being held    
steadily at ,d4 ,you should then shoot  
your lock two or three times1 to be sure
 you have made no mistake4 ,every time  
you shoot your bolts out1 turn your     
wheels away from the true chamber1 and  
see when you again turn your pointers to
 ,w ,o ,o ,d that your lock opens       
freely2 it is the proof that you have   
made no mistake1 and you may now venture
 to lock your safe4 ,when you unlock the
 door1 and find it necessary to leave it
 open for a time1 you should shoot the  
bolts as if locked1 and turn the wheels1
 so that no one may find what your real 
letters are2 and again adjust them to   
their proper places1 in order that the  

bolt may go back and enable you to      
re-lock4 ,once having locked the door   
and turned the wheels from your real    
letters1 you need not trouble yourself  
with carrying the key1 but leave it in  
any place beside the lock4  8,i believe 
two wheels would make a perfectly safe  
lock2 three would be quite so4 ,i       
adopted four to make security doubly    
sure1 as it would be impossible in any  
given time to work the changes4 ,on two 
wheels by chance the lock might open2   
you can1 however1 calculate the chances 
against this2 and also three or four1   
the false compartment on the outer rim  
being taken into calculation4    99   99
   99  8,if this lock is of any value1  
it should be known2 if it has weak      
points1 let them be pointed out1 and    
they may admit of a remedy2 for we ought
 not to be led to believe a lock is safe
 which is not so40  ,in relation to the 
8first advantage0 which ,mr4 ,brown not 
unreasonably supposed to be possessed by
 his lock--viz4 that 8it cannot be      

picked1 because it has no keyhole0--we  
shall have something to say in a future 
page1 where certain fallacies on this   
subject will be noticed4 ,in the        
meantime we may remark1 that it is not a
 little creditable that a leading       
,liverpool merchant should have invented
 a lock worthy of occupying a position  
on his own safe for a quarter of a      
century2 for we may be quite certain    
that he would not have allowed the lock 
to maintain that post of honour unless  
it had really 7so far as experience had 
then gone7 served worthily as a         
safeguard to his treasures4 ,and if it  
were possible to collect all the by-gone
 specimens of lock-oddities1 we should  
probably find among them many           
highly-ingenious letter-locks2 for      
supposing a man to have a mechanical    
turn of mind1 a lock is by no means an  
unworthy medium for displaying it2 the  
pieces of metal are so small as to be   
easily manageable at a small work-bench 
in a small room4 ,the fondness for this 

sort of employment evinced by the       
unfortunate ,louis ,,xvi4 of ,france led
 to the common remark1 8,he is a capital
 locksmith1 but a very bad king40  ,in  
an amusing article in the ,observer1    
during the progress of the 8lock        
controversy10 was the following         
paragraph relating to combination-locks 
of the letter or puzzle kind3 8,the     
,french1 in their exposition of #ahdd1  
availing themselves of the permutation  
principle1 produced some marvels in the 
art2 but the principle has not been     
adopted in this country4 ,the ,charivari
 had an amusing quiz upon these locks   
when they first came out4 ,it said the  
proprietor of such a lock must have an  
excellent memory3 forget the letters1   
and you are clearly shut out from your  
own house4 ,for instance1 a gentleman   
gets to his door with his family1 after 
a country excursion1 at eleven o'clock  
at night1 in the midst of a perfect     
deluge of rain4 ,he hunts out his       
alphabetical key1 and thrusts it into   

his alphabetical lock1 and says ,a ,z ,b
 ,x4 ,the lock remains as firm as ever4 
#8,plague take it6' says the worthy     
citizen1 as the blinding rain drives in 
his eyes4 ,he then recollects that that 
was his combination for the previous    
day4 ,he scratches his head to          
facilitate the movement of his          
intellectual faculties1 and makes a     
random guess ,b ,c ,l ,o2 but he has no 
better success4 ,in addition to his     
being well wet1 his chances of hitting  
on the right combinations and           
permutations are but small1 seeing that 
the number is somewhere about three     
millions five hundred and fifty-three   
thousand five hundred and seventy-eight4
 ,accordingly1 when he comes to the     
three-hundredth he loses all patience1  
and begins to kick and batter the door2 
but a patrol of the ,national ,guard    
passes by1 and the disturber of the     
streets is marched off to the           
watch-house40     ,,chapter ,,iv4       
,,warded ,,locks1 ,,with ,,their        

,,varied ,,appendages4   ,the more      
ordinary locks are of an oblong         
quadrangular shape4 ,in nearly all of   
them1 either a bolt shoots out from the 
lock1 to catch into some kind of staple 
or box1 or a staple enters a hole in the
 edge of the lock1 and is there acted   
upon by the bolt4 ,a common room-door   
lock will illustrate the first of these 
kinds1 a tea-caddy lock the second4 ,the
 key1 as is well known1 enters a        
receptacle made for it2 and the shaft of
 the key generally serves as a pivot or 
axis around which the web or flat part  
of the key may move in a circular       
course4 ,during this movement the web   
acts directly or indirectly on the bolt1
 driving it in or out according to the  
direction in which the key is turned2   
the key impels the bolt one way1 certain
 springs act upon it in another1 and the
 balance between these two forces       
determines the locking and unlocking of 
the bolt4 ,wards1 or wheels1 are        
contrivances for rendering the opening  

difficult without the proper key2 and it
 is of warded locks that we shall       
chiefly treat in this chapter4          
,illustration3 fig4 #f4 ,interior of a  
back-spring warded lock4  ,the annexed  
cut1 fig4 #f1 represents the interior of
 an ordinary back-spring lock1 without  
tumblers4 ,such a lock may usually be   
known from a tumbler-lock by this simple
 circumstance1 that it emits a smart    
snapping noise during the process of    
locking1 occasioned by the pressure of  
the spring when the bolt is in a        
particular position4 ,in the woodcut the
 bolt is represented half out1 or half  
shot4 ,at a a are two notches on the    
under side of the bolt connected by a   
curved part2 b is the back spring1 which
 becomes compressed by the passage of   
the curve through a limited aperture in 
the rim c c of the lock4 ,when the bolt 
is wholly withdrawn1 one of the notches 
a rests upon the rim c c2 and the force 
with which the notch falls into this    
position1 urged by the spring b1 gives  

rise to the snapping or clicking noise4 
,when the bolt is wholly shot1 the other
 notch rests in like manner upon the    
edge of the aperture in the rim4  ,it   
must be obvious at a glance1 that this  
back-spring lock is objectionable on the
 score of security1 on account of the   
facility with which the bolt may be     
forced back by any pressure applied to  
its end1 a pressure which may often     
easily be brought to bear4 ,at the      
centre of the lock is seen the end of   
the key acting on a notch in the bolt1  
and surrounded by wards4  ,illustration3
 fig4 #g4 ,section to shew the action of
 wards4  ,it is not at a first glance   
that the relation between the clefts in 
a key and the wards of a lock can be    
duly appreciated2 because the wards     
present themselves to view as portions  
of circles to which nothing in the key  
seems to correspond2 but if it be borne 
in mind that the key has a rotary motion
 within the key-hole around the pipe or 
barrel as an axis1 the circular form of 

the wards will be accounted for1 and    
their section will be regarded as       
exhibiting the looked-for relation to   
the wards of the key4 ,in the annexed   
cut1 for example 7fig4 #g71 which       
represents a portion of the interior of 
a warded lock1 the curved pieces of     
metal are the wards 7two in this case72 
and there are two clefts in the bitt of 
the key to enable the latter to take its
 circular course without interruption   
from the wards4 ,if the clefts were     
other than they are1 either in number1  
position1 or size1 this freedom of the  
key's movement could not be obtained4   
,illustration3 fig4 #h4 ,end sections of
 keys4  ,when once the opinion became   
established that a lock is rendered     
secure by virtue of its wards1 7a theory
 which we shall have to discuss in a    
later page17 much ingenuity was         
displayed in varying the wards of the   
lock1 the clefts of the key1 and the    
shape of the keyhole4 ,even if the two  
former were unchanged1 a change in the  

latter might add to the puzzlement of   
the arrangement4 ,for instance1 in the  
annexed cut 7fig4 #h71 all the six keys 
represented may have clefts or cuts     
exactly alike1 all alike adapted to the 
wards of one particular lock2 yet the   
differences in the thickness of the web 
are such1 that if the keyholes were     
shaped in conformity therewith1 each    
keyhole would be entered by one of these
 keys2 b and c differing from a in the  
relative thickness at different points1 
and d1 e1 and f having certain          
curvatures and cavities not to be found 
in the other three4  ,illustration3 fig4
 #i4 ,examples to shew the action of    
8master10 or 8skeleton keys40  ,but     
without waiting for the detailed        
examination of the relative security and
 insecurity of locks1 we may at once    
shew how simple is the principle which  
renders the warded system fallacious4   
,in fig4 #i we shall be able to         
illustrate this4 ,numbers #a1 #b1 and   
#c1 all appear very different keys1 and 

it is quite true that neither one would 
open a lock adapted for either of the   
other two2 and yet the very simple      
arrangement ,no4 #d would open all      
three4 ,this ,no4 #d is called a        
skeleton-key2 and the relation which it 
bears to the others may be expressed in 
the form of a proposition thus3 at any  
point where there is solid metal in all 
the keys1 there must 7or may7 be solid  
metal in the corresponding part of the  
skeleton-key2 but at any point where    
there is a vacancy or cavity in any of  
the keys1 there must be a cavity in the 
corresponding part of the skeleton-key4 
,if ,nos4 #a1 #b1 #c1 #d1 be examined1  
this proposition will be found to be    
borne out2 there is so much cavity in   
,no4 #d that it avoids the wards in all 
the three locks1 nothing being required 
but the tongue of metal to move the     
bolt4 ,sometimes1 to add to the safety1 
wards are attached to the front as well 
as the back plate of the lock2 and then 
there may be a double series of notches 

required in the key1 such as in ,no4 #e2
 but if this be compared with ,nos4 #i1 
#aj1 #aa1 it will be found that although
 no one of the four would open a lock   
adapted for either of the other three1  
yet the skeleton-key ,no4 #ab would     
master them all1 having cavities        
wherever any of the others have         
cavities4 ,this is the theory of the    
master-key1 by which one key may be made
 to command many locks4 ,nos4 #f and #g 
have complicated wards2 but the key is  
so much cut up as to be weakened more   
than is desirable4 ,no4 #h enables us to
 point out the difference between two   
distinct classes of keys4 ,keys with    
pipes or barrels fitting on a pin or    
pipe-shaft can only open a lock on one  
side of the door or box2 but a key with 
a solid stem1 as ,no4 #h1 has the clefts
 so cut as to open the lock from either 
side1 as in a street-door lock3 it is1  
in fact1 two warded keys fixed end to   
end1 only half of which is employed at  
one time in opening the lock4           

,illustration3 fig4 #aj4 ,wards of an   
old ,french lock4  ,some of the warded  
locks of the last century are curious4  
,while the idea prevailed that a        
complicated ward gave security1 there   
was room for the exercise of ingenuity  
in varying the shape of the wards4 ,fig4
 #aj is copied from the great ,french   
work4 ,it represents the cuts in the    
key1 and also 7seen perspectively7 the  
complicated forms of the pieces of metal
 which constitute the wards             
corresponding with those cuts4 ,the     
aperture in the key at #af fits upon the
 metal surrounding the keyhole at #ah2  
and the ,m-shaped cuts at #ag fit in    
like manner upon the similarly-shaped   
metal pieces at #ai4  ,another example  
of a similar kind is shewn in fig4 #aa1 
where an anchor appears to have been the
 favourite form4 ,the anchor cuts in the
 key are shewn at #bf2 while in the     
wards the bottom of the anchor is near  
the keyhole at #bh1 and the top at #bi4 
,illustration3 fig4 #aa4 ,wards of an   

old ,french lock4  ,illustration3 fig4  
#ab4 ,wards of an old ,french lock4  ,a 
similar illustration occurs in fig4 #ab1
 where the star-like cuts at #cd on the 
key correspond with the star-like wards 
at #cc4  ,illustration3 fig4 #ac4       
,exterior of an old secret lock4        
,illustration3 fig4 #ad4 ,the same1 with
 a portion of the front let down1       
shewing the key-hole4  ,from the        
fifteenth to the eighteenth centuries   
locks were made in ,france1 on which a  
vast amount of care and expense was     
bestowed4 ,they were1 in an especial    
degree1 decorative appendages as well as
 fastenings4 ,they were of three kinds3 
room-locks1 buffet-locks1 and           
chest-locks2 they were fixed on the     
outside of the door or lid1 so as to be 
fully visible4 ,the key had a multitude 
of perforations which bore no particular
 relation to the wards of the lock1 but 
which were regarded as tests of the     
workman's skill4 ,the honorary          
distinctions awarded to apprentices and 

aspirants in the art depended very much 
on the number and fine execution of     
these perforated keys4 ,the locks1      
considered as fastenings1 had slender   
merit2 although usually throwing four   
bolts1 they were not very secure4 ,fig4 
#ac represents the exterior of a lock   
made about the year #agcj1 by ,bridou1 a
 celebrated ,parisian locksmith4 ,it was
 a lock belonging to a coffer or strong 
chest2 all the works being sunk below   
the level of a carved architectural     
moulding or ornament4 ,there is a secret
 opening near the part ,c1 forming a    
portion of the ornamental design2 it    
allows a bolt1 shewn at ,d1 fig4 #ad1   
acted on by the spring ,e1 to be        
touched1 by which a doorway opens upon  
the hinges at ,b ,b4 ,a ,a are a sort of
 pilasters1 which aid in forming a hold 
for the bolts4 ,the little ornament at  
,c is drawn down by the hand1 opening   
the secret door and revealing the       
key-hole ,g4 ,s ,s1 ,o ,o1 ,z ,z1 are   
ornaments fastened on at b c d1 fig4    

#ad1 by nuts and screws1 intended to    
display the skill of the workman4 ,the  
lock itself1 access to the keyhole of   
which is obtained within the secret     
door1 has nothing very remarkable about 
it4  ,illustration3 fig4 #ae4 ,examples 
of true and false keys4  ,mr4 ,chubb1 in
 his paper read before the ,institute of
 ,civil ,engineers1 illustrated the     
insecurity of the warded lock by the    
example of one which had actually been  
placed in the strong-room of a banking  
house1 and which is represented in the  
annexed cut 7fig4 #ae74 ,the wards are  
here shewn1 surrounding the central     
key-pin2 and from the appearance of the 
key1 shewn at a1 it is evident that     
these wards must have been rather       
complex4 ,but the uselessness of the    
wards was proved by the result4 ,a      
burglar employed an instrument1 shaped  
like that at b1 having on one of its    
faces1 or sides1 a layer of wax and     
yellow soap2 this instrument1 being     
introduced through the keyhole and      

turned a little way round1 brought the  
soft composition in contact with the    
ends of the wards1 and these ends thus  
left their impress on the composition4  
,a false key was then made1 as at c1    
which1 however clumsy it may appear1 has
 a cavity1 or vacuity1 where there is a 
cavity in the true key2 and by such a   
surreptitious instrument was the lock   
opened4 ,even so rude an instrument as  
d1 by passing round the wards1 might    
open such a lock4  ,we are somewhat     
anticipating the full consideration of  
this subject2 but it is desirable at    
once to explain how and why an          
improvement on the warded lock was      
sought for4  ,in connexion with the     
fanciful eighteenth-century locks1      
lately adverted to1 we may remark1 that 
no less a man than ,louis ,,xvi4 was an 
amateur workman in this department of   
mechanical art--or at least in smith's  
work1 which in ,france is generally     
considered to include lock-making4 ,sir 
,archibald ,alison says1 in his ,history

 of ,europe3--8,he had an extraordinary 
fondness for athletic occupation and    
mechanical labour2 insomuch that he     
frequently worked several hours a-day   
with a blacksmith of the name of ,gamin1
 who taught him the art of wielding the 
hammer and managing the forge4 ,he took 
the greatest interest in this           
occupation1 and loaded his preceptor in 
the art with kindness2 who returned it  
by betraying to the ,convention a secret
 iron recess which they had together    
worked out in the walls of the cabinet  
in the ,tuileries1 wherein to deposit   
his secret papers during the storms of  
the ,revolution40 ,there are not wanting
 indications that the unfortunate       
monarch wrought upon locks1 as well as  
upon safes and strong-rooms4  ,besides  
wards1 there have been numerous other   
contrivances for adding to the security 
of locks--including screws1 escutcheons1
 spiral springs1 wheel-and-pinion work1 
alarums1 and multiple bolts4 ,as these  
are not of sufficient importance to be  

treated in separate chapters1 we shall  
here give just so much notice of them as
 will illustrate their general          
character4 ,some of them are found      
combined with the 8tumbler0 principle1  
presently to be described2 but all of   
them1 it is now well known1 were        
employed in various1 ways when the      
tumbler lock was but little understood1 
and when the warded lock was held in    
esteem4  ,the ,marquis of ,worcester1   
whose curious ,century of ,inventions1  
written nearly two hundred years ago1   
contains so many suggestions which      
ingenuity has since developed into      
practical completeness1 gives four of   
his inventions in the following words3--
  #fi4 8,a way how a little triangle    
screwed key1 not weighing a shilling1   
shall be capable and strong enough to   
bolt and unbolt1 round about a great    
chest1 an hundred bolts1 through fifty  
staples1 two in each1 with a direct     
contrary motion2 and as many more from  
both sides and ends2 and1 at the        

self-same time1 shall fasten it to the  
place beyond a man's natural strength to
 take it away2 and in one and the same  
turn both locketh and openeth it4  #gj4 
8,a key with a rose-turning pipe and two
 roses pierced through endwise the bit  
thereof1 with several handsomely        
contrived wards1 which may likewise do  
the same effects4  #ga4 8,a key1        
perfectly square1 with a screw turning  
within it1 and more conceited than any  
of the rest1 and no heavier than the    
triangle screwed key1 and doth the same 
effects4  #gb4 8,an escutcheon1 to be   
placed before any of these locks1 with  
these properties3 ,first1 the owner1    
though a woman1 may with her delicate   
hand vary the ways of causing to open   
the lock ten millions of times beyond   
the knowledge of the smith that made it1
 or of me that invented it4 ,second1 if 
a stranger open it1 it setteth an alarum
 a-going1 which the stranger cannot stop
 from running out2 and besides1 though  
none shall be within hearing1 yet it    

catcheth his hand as a trap doth a fox2 
and though far from maiming him1 yet it 
leaveth such a mark behind it as will   
discover him if suspected2 the          
escutcheon or lock plainly shewing what 
money he hath taken out of the box to a 
farthing1 and how many times opened     
since the owner had been at it40  ,mr4  
,partington1 in his edition of the      
marquis's singular work1 makes a few    
comments on these lock-and-key          
contrivances4 ,he says that the lock is 
evidently intended to operate on the    
principle of applying a screw for the   
purpose of moving the bolt1 instead of  
using a key as a lever for this purpose4
 ,that such a plan might be applied to  
locks generally1 he observes1 there can 
be no doubt2 and by a similar           
contrivance the large keys at present in
 use for outer doors1 iron chests1 c4   
might be advantageously reduced by this 
means4 ,by employing the escutcheon     
mentioned by the marquis1 much          
additional security would be obtained4  

,it must be confessed1 however1 that    
many of the marquis's statements are    
difficult to credit4  ,the escutcheon   
has been a favourite resource with      
lock-makers4 ,mr4 ,mordan's escutcheon1 
for instance1 introduced before the     
,society of ,arts in #ahcj1 is a        
contrivance to be placed temporarily    
over the keyhole of a door1 to prevent  
the picking of the lock during the      
owner's absence4 ,the escutcheon1 or    
8protector10 has a short pipe which1    
after the door has been locked1 is      
thrust into the keyhole2 attached to the
 pipe is a small lock1 on ,bramah's or  
any other convenient principle1 so      
contrived that1 on turning its key1 two 
lancet-shaped pieces fly out laterally  
and bury themselves in the wood4 ,the   
escutcheon cannot be removed until the  
small key has reacted upon the small    
lock2 and until this removal has taken  
place1 the large key cannot reach the   
keyhole4  ,a curious application of the 
escutcheon principle attracted some     

attention among locksmiths about seventy
 years ago4 ,one of the first premiums  
awarded by the ,society of ,arts1 after 
the commencement of their               
8,transactions10 was to ,mr4 ,marshall1 
for a 8secret escutcheon10 in #aghd4 ,in
 his description of his new invention1  
he adverts to the marquis of            
,worcester's wonderful escutcheon1 and  
to the many attempts which have since   
been made to produce an apparatus which 
should realise the marquis's            
description4 ,he supposes that the      
letter padlock originated as one among  
many varieties of these imitative       
inventions2 but this may be doubted4    
,mr4 ,marshall's contrivance1 however1  
was in effect an endeavour to improve   
upon the letter-lock4 ,he considered it 
an objection that1 in ordinary locks of 
this kind1 the letter-rings admit of no 
variation of place2 and he sought to    
remedy this defect4 ,it is not so much a
 new lock1 as an escutcheon for a lock1 
which he produced4 ,there is a studded  

bar passing through a barrel2 there are 
five rings which work concentrically on 
this barrel2 there are letters on the   
outer surfaces of the rings1 and notches
 on the inner surface2 but when1 by the 
usual puzzle-action of the rings1 the   
notches in them have been brought into a
 right line with the studs of the bar1  
the result is1 not that the hasp of a   
padlock is raised1 but that the         
escutcheon is removed from the keyhole  
of an ordinary lock4 ,mr4 ,marshall's   
contrivance1 therefore1 is not so much a
 ring padlock1 as a puzzle-ring security
 for the escutcheon of a fixed lock4    
,some locks work by a screw and a spiral
 spring1 instead of an ordinary key4    
,mr4 ,w4 ,russell received a silver     
medal from the ,society of ,arts1 about 
thirty years ago1 for a new mode of     
locking the cocks of liquor-casks4      
,under ordinary circumstances1 as is    
well known1 the cock of a barrel or cask
 is in no way secure from the action of 
any one who can approach near enough to 

touch it2 and different methods have    
been adopted of obtaining this security 
or secrecy4 ,one plan is to employ a    
perforated cap1 soft-soldered to the    
barrel of the cock1 immediately over the
 grooved plug1 the top of which plug is 
formed to the shape of the perforation1 
and a socket-key of the same form is    
introduced to turn the plug or open the 
lock4 ,another plan is to employ an iron
 saddle or staple1 passing over the plug
 and below the bottom of the cock1      
through which a bolt is put1 and a      
pendent padlock attached4 ,the first    
method is very inefficient2 the second  
is much superior1 and has been largely  
adopted for locking the cocks of        
coppers1 stills1 vats1 and other large  
vessels4 ,but ,mr4 ,russell thought some
 further improvement wanted4 ,he caused 
a hole to be bored through the barrel1  
and to some depth into the plug when the
 latter is in the position for closing  
the cock4 ,a stud works into this hole  
in such a way1 that when the stud is    

driven home1 the plug cannot be turned  
or the lock opened4 ,the stud is        
attached at its other end to a spiral   
spring connected with a screw2 a key is 
employed1 the hollow pipe of which has  
an internal screw2 and when this key is 
inserted in the cock-barrel and turned  
twice round1 it draws back the stud1 and
 allows the plug to be turned round in  
the proper way for opening the cock4    
,it is not often that wheel-and-pinion  
work is introduced into locks2 the      
delicacy1 the costliness1 the weakness1 
and the tendency to get out of order1   
would all militate against the frequent 
adoption of such a course4 ,it is1      
however1 adopted occasionally4 ,mr4     
,friend's secret-lock1 introduced to the
 notice of the ,society of ,arts in     
#ahbe1 had a train of wheels which acted
 upon the bolt1 driving it out whenever 
the circular arcs of three wheels moved 
against it1 but allowing a spring to    
force it back again whenever a deep     
cleft in each of the wheels locked into 

a stud on the bolt4 ,there were certain 
numbers on a guide-plate1 and a power of
 combining these numbers in great       
variety2 and a provision that the bolt  
could be unlocked only by the same      
combination of numbers which had locked 
it4 ,the guide-plate was a separate     
piece of apparatus1 carried in the      
pocket of the user as a companion to the
 key4 ,the key was of no use without the
 guide-plate1 nor the guide-plate       
without the key4 ,the user #8set' the   
numbers on the guide-plate1 then applied
 it to the face of the lock1 then       
introduced the key into the key-hole1   
and turned the key partially round2 the 
bolt was now shot1 and the guide-plate  
removed4 ,if the key were used without  
the guide-plate1 the bolt might be      
locked1 but it was always unlocked again
 by the time the key had made a complete
 circuit4 ,there was considerable       
ingenuity in the idea of this lock2 but 
we believe it never went further than a 
model4 ,indeed many of the locks        

elaborately described in books have     
never had an existence as acting working
 locks4  ,a very ingenious principle has
 been occasionally introduced1 in which 
clock-work regulates the interval of    
time which must elapse before a lock can
 be opened1 even with its proper key4   
,the object is1 to ensure the safety of 
the lock during a journey1 or until a   
particular person be present1 or until  
the locked article is conveyed to a     
particular room4 ,a patent was taken out
 in #ahca for a lock on this principle  
by ,mr4 ,rutherford1 a bank agent at    
,jedburgh4 ,against the end of the bolt 
of the lock is placed a circular        
stop-plate1 so adjusted that the bolt   
cannot be withdrawn until a particular  
notch in the rim of the circular plate  
is opposite the end of the bolt4 ,the   
plate is put in rotation by clock-work4 
,as the notch can be set at pleasure to 
any required distance from the end of   
the bolt1 the lock may be secured       
against being opened1 either by its own 

or any other key1 until any assigned    
number of minutes or hours after it has 
been locked2 for the plate may be made  
to revolve either slowly or quickly1 by 
varying the number of wheels in the     
clockwork4 ,when the lock is used for   
boxes or portable packages1 the         
clockwork must be moved and regulated by
 a spring2 but when it is applied to    
closets or safes1 a descending weight   
and a pendulum may be employed4 ,it is  
manifest that this system is susceptible
 of being greatly varied in its mode of 
application2 and it has many points of  
interest about it4 ,that a man cannot   
open his own lock with his own proper   
key1 until the lock gives permission by 
assuming a particular state or          
condition1 certainly strikes one as     
being susceptible of many useful        
applications1 where time is an element  
taken into the account4  ,a curious     
alarum-lock was invented by ,mr4        
,meighan1 in #ahcf1 in which the bell or
 alarum is not placed behind a door1 as 

in many alarum contrivances1 but within 
the lock itself4 ,two or more studs are 
placed on the bolt1 which press against 
the lower end of a small tumbler2 the   
movement of the tumbler elevates a      
hammer2 but as soon as the point of the 
tumbler becomes released from the stud1 
a spring presses the hammer down        
forcibly1 and causes it to strike       
against a small bell placed near it4    
,this sounding of the bell will be      
repeated1 during the shutting of the    
bolt1 as many times as there are studs  
to act upon the point of the tumbler4   
,much of the ingenuity which has been   
displayed in locks depends on the       
employment of multiple bolts1 there     
being all the additional strength which 
results from the use of two or more     
bolts instead of simply one4 ,ordinary  
doors seldom afford us examples of these
 double bolts2 but they may be          
frequently seen in cabinets and desks1  
where two staples fixed to the lid fall 
into two holes in the lock1 and are     

retained by two bolts4 ,the most        
remarkable and complicated varieties1   
however1 are those in which the bolts1  
instead of shooting parallel and nearly 
together1 shoot in wholly different     
ways2 one up1 one down1 one to the      
right1 one to the left1 and so on4 ,it  
is on safes1 strong boxes1 and the doors
 of strong rooms containing valuable    
treasures1 that such locks are usually  
placed4 ,the mechanism is such that the 
key acts upon all the bolts at once1    
through the intervention of levers and  
springs of various kinds4               
,illustration3 fig4 #af4 ,multiple bolts
 of an old chest-lock4  ,the above      
woodcut represents a very curious       
specimen of these multiple-bolt locks4  
,it is copied from the great ,french    
work2 and the ponderous chest to which  
it is attached is1 we are told by       
,raumur1 8known at ,paris by the name of
 the strong ,german coffer40 ,he further
 says1 8nothing is wanting in these     
coffers on the score of solidity4 ,they 

are made entirely of iron2 or if of     
wood1 they are banded both within and   
without with iron2 and can only be      
broken open by very great violence4     
,their locks are almost as large as the 
top of the coffer1 and close with a     
great number of bolts4 ,the one which we
 have engraved has twelve fastenings2   
they have been made with twenty-four1 or
 more40 ,his next remark on the subject 
is a sensible one3 8,notwithstanding the
 large size of these locks1 and all the 
apparatus with which they are provided1 
they correspond but ill with the        
solidity of the rest of the coffer4 ,if 
we have given a representation of one1  
it is chiefly to shew how little        
confidence one could have in such a     
lock1 and what are its defects1 in order
 that we may avoid them40 ,it is not    
difficult1 by tracing the action of the 
several levers1 to see how one movement 
of the key1 in the centre of the lid1   
would act upon all the bolts4 ,in the   
engraving 7fig4 #af7 a1 f1 h1 c1 are the

 four corner bolts2 six others1 a d e1 a
 d e1 are on the long sides1 three on   
each2 and two1 b g1 on the short sides4 
,every bolt is provided with a spring1  
of which three or four are shewn at ,z  
,z ,z4 ,there is no staple or box to    
receive each bolt2 but all shoot or snap
 beneath the raised edge ,e running     
round the top of the box just within the
 exterior at ,a ,a4 ,the keyhole in the 
front of the box at ,d is a deception or
 mask2 the real keyhole is in the middle
 of the lid concealed by a secret door  
opened by a spring4 ,when the key has   
moved the great central bolt1 this acts 
upon the other bolts ,p ,q ,r ,s ,t1 c42
 ,v ,v are studs which act upon two of  
the bolts2 ,y ,y are staples confining  
the great bolt2 k1 l1 c1 p1 x1 are small
 levers which transmit the action to the
 corner bolts2 q1 r1 s1 t1 n1 are the   
small levers which render a similar     
service to the side and end bolts2 ,l ,l
 within the chest1 and ,m ,m on the lid1
 are contrivances for limiting the      

movement of the latter2 ,c ,h1 ,h ,c are
 iron straps or bands by which the      
interior of the chest is strengthened4  
,after all1 this is not so much a lock  
as a series of spring latches4  ,if a   
lock can be picked1 the picking is as   
effective whether the lock has one bolt 
or twelve bolts4 ,this fact led ,mr4    
,duce1 in #ahbd1 to construct1 instead  
of a four-bolt lock1 four distinct      
one-bolt locks1 fixed in the same frame 
and opened by the same key2 the bolts to
 be moved in succession instead of      
simultaneously4 ,it would require four  
times as long to pick this as a         
four-bolt lock of similar action4       
,there have been many other varieties of
 the multiple bolt1 but we need not stop
 to describe them4     ,,chapter ,v4    
,,on ,,tumbler1 ,,or ,,lever ,,locks4   
,security being the primary object in   
all locks1 any considerations as to     
mechanical ingenuity and graceful       
decoration give place to those which    
relate to safety4 ,a spring lock may be 

ingenious and even beautiful in its     
construction1 but an imitative key will 
easily open it4 ,hence arose the        
invention of wheels or wards2 and as    
wards failed in trustworthiness1 they in
 their turn yielded to something better4
 ,we have already explained how the     
insecurity of mere warded locks arises2 
and we shall have something more to say 
on the subject in a future chapter4 ,it 
is sufficient here to remark1 that      
wards1 springs1 screws1 alarums1        
wheel-work1 escutcheons1--all1 however  
useful for particular purposes1 are     
wanting in the degree of surety which we
 require in a lock4 ,hence the invention
 of tumblers1 levers1 or latches1 which 
fall into the bolt and prevent it from  
being shot until they have been raised  
or released by the action of the key4   
,we have been unable to ascertain at    
what time1 or in what country1 or by    
whom1 tumbler-locks were invented4 ,the 
invention has been claimed by or for    
persons subsequently to the year #agfg1 

when the celebrated ,french treatise    
7,art du ,serrurier7 already referred to
 was published2 and yet this treatise   
contains numerous examples of simple    
tumbler locks of ingenious construction1
 as will presently be shewn4            
,illustration3 fig4 #ag4 ,simple tumbler
 lock4  ,one of the most elementary     
forms of tumbler-lock is shewn in fig4  
#ag4 ,in this case the bolt1 instead of 
having two notches in the bottom edge1  
like those in the back-spring lock1 fig4
 #f1 has two square notches or slots in 
the upper edge2 and as the key acts upon
 the bolt1 these notches must of course 
share in whatever movements the bolt is 
subjected to4 ,behind the bolt is a kind
 of latch or tumbler 7the lower part of 
which is shewn by dotted lines71 with a 
stump or projecting piece of metal at a2
 the tumbler moves freely on a pivot at 
the other end1 and is made to rise      
through a small arc whenever the key    
acts upon the bolt4 ,when the bolt is   
wholly shot1 the stump falls into one   

notch and prevents the motion of the    
bolt2 when wholly unshot or withdrawn1  
the stump falls into the other notch1   
and equally prevents the motion of the  
bolt4 ,it is not1 therefore1 until the  
key1 by elevating the tumbler1 has      
raised the stump out of the notch1 that 
the bolt has freedom of movement4 ,if   
the shape of the key does not enable its
 web to effect this elevation to a      
sufficient degree1 the bolt remains     
immovable2 and to this extent a certain 
additional security is obtained by      
making the shape of the key significant 
as well as the wards4  ,illustration3   
fig4 #ah4  ,illustration3 fig4 #ai4 ,old
 ,french lock4  ,the tumbler-principle1 
as we have said1 is difficult to trace  
to its origin on account of the various 
aspects which it presents2 but the great
 ,french treatise proves that the       
locksmiths of ,france were familiar with
 tumbler-locks a century ago4 ,the      
plates of that work represent the       
details of numerous locks1 on the upper 

edge of the bolts of which were notches 
called encoches1 as at o k fig4 #ah2    
into these notches sank a small iron    
stud or stump called the arrt du pne1 or
 bolt-stop1 shewn in fig4 #ai1 attached 
to the upper portion of the gchette or  
tumbler1 which1 for the sake of economy 
of metal1 is made in the form of a      
triangular spring in front of the bolt k
 i2 and not until the key1 by its       
circular action1 had raised this stud   
out of one or other of the notches1     
could the bolt move to the right or     
left4 ,the stud was generally fixed to a
 spring which forced it down again into 
the notch as soon as the action of the  
key had ceased4 ,sometimes1 however1 the
 stud was fixed to the bolt1 and the    
notches were in a separate tumbler or   
gchette 7see ,e ,e1 fig4 #ba72 and in   
other instances1 again1 the stump was   
fixed to the case of the lock and caught
 into notches in the bolt4 ,it will be  
seen1 when we come to treat of          
tumbler-locks of later date1 that there 

was much in these early locks to point  
out the way4 ,fig4 #ai1 copied from the 
,french work1 represents a lock of the  
box or casket kind4 ,two staples1 fixed 
into the cover1 fall into two cavities  
or receptacles at ,c d2 and a short bolt
 in each receptacle catches into each   
staple1 one near g and one near h4 ,the 
small bolt q is attached to the upper   
extremity of the lever q r s1 fig4 #ai1 
and shewn separately in fig4 #bj2 and by
 the pressure of a spring a 7fig4 #ai7  
upon this lever1 the bolt q is kept     
locked in the staple4 ,the vertical     
portion of this spring presses at its   
lower end on another spring p 7fig4 #ai7
 of singular curvature2 and attached to 
the horizontal part of this second      
spring is the stud1 which falls into a  
notch in the top of the bolt4 ,the      
action of these parts1 then1 is as      
follows3 when the key is placed upon the
 key-pin at ,z1 and turned round in the 
direction in which the hands of a watch 
move1 the bitt presses against the tail 

s of the lever1 moves it upon its centre
 ,z1 fig4 #ai1 v1 fig4 #bj1 to the left1
 and consequently moves the upper part q
 to the right1 drawing it out of the    
receptacle and liberating the staple    
within ,c4 ,thus it will be seen that   
the lever q r s1 held in one position by
 the spring a1 forms in itself a simple 
kind of spring catch-lock1 and was1 in  
fact1 formerly used as such1 without any
 other appendages except the staple in  
the lever1 into which the catch q fitted
 on shutting down the lid4 ,so also we  
may regard the other portion1 fig4 #ah1 
or k i p h 7fig4 #ai71 as forming a     
separate lock2 for the key after having 
passed ,s comes in contact with the     
triangular spring1 which it raises      
thereby1 lifting the stud out of the    
bolt1 and exerting pressure against the 
barbs of the bolt n4 ,fig4 #ah shoots   
the bolt k1 and also the short bolt l1  
which passes through the staple in the  
cavity d1 fig4 #ai4  ,illustration3 fig4
 #bj4  ,the lock represented in the four

 following figures is also from ,m4 de  
,raumur's chapter on locks in the work  
referred to4 ,in this lock the          
tumbler-principle is carried out in a   
very elaborate manner1 for not only is  
the stump or stud ,h 7fig4 #bc7 attached
 to a very strong spring 7best shewn at 
,h1 fig4 #bb71 which holds it with      
considerable force in one of the three  
notches of the principal bolt ,r ,s     
7fig4 #bd72 but there is also a second  
set of notches ,e ,e in the gchette ,g  
,o 7fig4 #ba71 and a pin attached to one
 of the plates of the lock fits into one
 of these notches1 thereby preventing   
the bolt from being moved until the     
gchette is lowered by the revolution of 
the key2 so that in attempting to pick  
this lock1 not only must the spring ,h  
be raised so as to release the stud from
 the notches of the great bolt1 but the 
gchette must be lowered to disengage the
 fixed pin from the notches4 ,there is  
yet a third source of security4         
,attached to the large bolt are short   

projecting pins ,f 7fig4 #ba71 against  
which an arm or detent1 ,g ,f1 of the   
gchette projects1 thus preventing the   
bolt from being shot back by any        
pressure applied to its extremity ,s4   
,illustration3 fig4 #ba4 ,details of an 
old ,french lock4  ,illustration3 fig4  
#bb4 ,another view of the same4         
,illustration3 fig4 #bc4 ,another view  
of the same4  ,illustration3 fig4 #bd4  
,the two bolts detached4  ,there are a  
few details relating to this remarkable 
lock1 which may as well be introduced   
here in order to complete the           
description4 ,the principal bolt can be 
shot twice1 or be double-locked2 hence  
it is furnished with three barbs for the
 key to act against1 and with three     
notches for the spring-stud4 ,the lower 
bolt ,i ,k can be shot by the horizontal
 pressure of the button ,p 7figs4 #bb1  
#bc71 which is situated on the inner    
side of the door to which this lock is  
attached1 so that a person inside the   
room can secure the door against any one

 on the outside who is not furnished    
with the proper key1 for it must be     
remarked that the small bolt as well as 
the large one is acted on by the key4   
,now supposing the small bolt to be shot
 or locked1 it is kept so by the        
pressure of the coiled spring ,q 7figs4 
#ba1 #bb74 ,but this small bolt is      
connected with the large one by means of
 the bent lever ,o ,n ,m 7figs4 #ba1    
#bd71 which turns on a pin ,n attached  
to the main bolt4 ,now1 when both bolts 
are either fully shot or unshot1 the arm
 ,o ,n lies flat against and parallel   
with the main bolt2 but when the large  
bolt is unshot and the small one not    
moved1 the arms ,o ,n1 ,n ,m1 fall into 
an inclined position1 and the arm ,o ,n 
passing a little below the main bolt    
comes within the range of the web of the
 key1 which in its revolution causes the
 bent lever to move upon its centre ,n1 
thereby restoring ,o ,n to its          
horizontal position1 and at the same    
time causing the arm ,n ,m to move from 

right to left1 or in the direction for  
unshooting the small bolt2 the end of   
this arm thus catches into a mortise ,v 
7figs4 #ba1 #bd7 in the small bolt1 and 
immediately unlocks it4  ,but to return 
to the subject of tumbler-locks4 ,about 
the year #aggh1 ,mr4 ,barron introduced 
that species of double-action 7as it may
 perhaps be termed7 which so greatly    
increases the security of the simple    
tumbler1 fig4 #ag4 ,in the tumbler-locks
 previously made1 if the tumbler were   
raised sufficiently high1 the lock could
 be opened3 there was no such           
possibility as raising it too high2 but 
,mr4 ,barron1 by his invention1 patented
 #cast ,october1 #aggh1 rendered it     
absolutely necessary that a limit should
 be put to the height to which the      
tumbler should be raised1 by rendering  
the bolt equally immovable whether the  
tumbler were too much or too little     
raised4 ,another important improvement  
was the introduction of two tumblers    
instead of one4 ,the bolt has in its    

middle a slot or gating notched on both 
edges1 the notches being fitted for the 
reception of studs fixed to the         
tumblers4 ,supposing the studs or stumps
 of the tumblers to be resting in the   
lower notches1 they require to be       
elevated to the general level of the    
gating before the bolt can be moved2    
whereas1 on the other hand1 if the      
tumblers were raised ever so little too 
high1 the studs will enter the upper    
notches1 and prevent the shooting of the
 bolt4 ,the lower edge1 or belly1 of    
each tumbler is acted on by the steps of
 the key during its circular movement2  
the leverage of the key being so exactly
 adjusted as to raise the tumbler to the
 desired height and no further4 ,the    
tumblers are made unequally wide1 so    
that steps or inequalities in the bit of
 the key are requisite to lift them both
 to the proper height4 ,there are thus  
two improvements introduced3 there are  
two tumblers instead of one1 and each   
tumbler has a double instead of a single

 action4  ,this ingenious and very      
useful lock is represented1 so far as   
regards its governing principle1 in fig4
 #be4 ,the bolt is here seen to have a  
peculiar slot or hole cut in it1        
consisting of a narrow horizontal       
passage or gating1 with three notches   
above it and three below it4 ,these     
double notches might be available even  
for one tumbler only2 but ,barron used  
two or more for the sake of additional  
security4 ,in fig4 #be there are two    
tumblers shewn1 expressed by dotted     
lines2 both are hinged to one pivot1    
both are raised by the same action of   
the key1 but the stump on the one       
tumbler does not coincide in position   
with that on the other4 ,it will be seen
 that if the studs of the tumblers      
rested in the lower notches1 they would 
require to be elevated to the level of  
the gating before the bolt could be     
moved2 while1 on the other hand1 if     
lifted too high1 the stumps would be    
caught in the upper notches1 and would  

equally prevent the passage of the bolt1
 ,the tumblers are unequally wide2 and  
the bitt of the key is stepped or       
notched in a corresponding way1 that    
there may be one step fitted to act upon
 each tumbler4 ,mr4 ,barron also adopted
 the reverse arrangement of having the  
stump on the bolt1 and the openings in  
the tumblers2 so that the principle of  
his patent may be concisely expressed as
 being 8an arrangement to allow a stump 
on the tumbler to pass through an       
opening in the bolt1 or a stump on the  
bolt to pass through an opening in the  
tumbler40  ,illustration3 fig4 #be4     
,action of ,barron's tumbler-lock4  ,a  
very elaborate tumbler-lock1 patented   
#bc;d ,february1 #agij1 by ,mr4         
,rowntree1 contrasts remarkably with the
 simplicity of ,barron's lock4 ,mr4     
,rowntree's lock consisted of tumblers  
combined with revolving discs or wheels4
 ,its mechanism may be understood from  
the following description and           
engravings4 ,the same letters refer to  

the same parts in the several figures4  
,illustration3 fig4 #bf4  fig4 #bg4     
fig4 #bh4  fig4 #bi4  fig4 #cj4         
,details of ,rowntree's tumbler-lock4   
,a ,a is the plate which encloses the   
whole mechanism of the lock1 and fastens
 it to the door2 ,b ,b is the bolt1     
guided in its motion by sliding under   
the bridges ,c ,d2 ,e ,e are pillars    
which support a plate covering the      
works2 ,f are the circular wards        
surrounding the centre or key-pin2 and a
 shews the position of the key1 which1  
in turning round1 acts in a notch r in  
the bolt1 and propels it2 ,g1 the       
tumbler1 is a plate situated beneath the
 bolt1 and moving on a centre-pin at d2 
it has a catch or stump e projecting    
upwards1 which enters the notches s or g
 in the bolt1 and thereby retains the   
latter for backward or forward motion1  
as the case may be2 ,h is a spring which
 presses the tumbler forward4 ,the key  
a1 in turning round1 acts first against 
the part c c of the tumbler1 and raises 

it so as to remove the stump from the   
notches2 it can then enter the notch r  
in the bolt1 and move it4 ,so far there 
is no particular security2 but ,mr4     
,rowntree sought to obtain it by the    
following means4 ,there is a piece of   
metal h fixed to the lower side of the  
tumbler1 called the pin2 when the       
tumbler is caught in either notch of the
 bolt1 the pin applies itself to a      
cluster of small wheels ,i1 fitted on   
one centre-pin beneath the tumbler2 the 
edges of these wheels stop the pin1 and 
prevent the tumbler from being raised4  
,but each wheel has a notch cut in its  
circumference ,i2 and it is only when   
the wheels are so placed that all their 
notches lie in a right line1 that the   
pin can enter this compound notch and   
allow the tumbler to rise4 ,the wheels  
must therefore be all adjusted to       
position2 and this is effected by a     
number of levers ,k centred on one pin  
at k2 at the opposite end each lever has
 a tooth m entering a notch in the wheel

 belonging to it2 so that when any lever
 is pressed outward1 it turns its wheel 
round4 ,now this pressure of the levers 
is brought about by a spring n applied  
to each2 and when so pressed1 the levers
 rest against a pin o fixed in the      
plate4 ,the key is so cut as to         
determine the extent to which the levers
 shall act upon the wheels4 ,the key    
first operates from the curved part p p 
of the levers ,k1 and raising them1     
turns all the wheels ,i at once into the
 proper positions2 in turning further   
round1 it then operates on the part c c 
of the tumbler1 causing the latter to   
rise and to release the bolt2 and in    
turning still further round1 it 7the    
key7 seizes the notch r of the bolt1 and
 shoots it4 ,the key is cut into steps  
of different lengths1 as shewn at ,v ,v2
 each step operates on its respective   
lever ,k in a different degree from the 
others2 the notch at s acts upon the    
tumbler1 and the plain part t moves the 
bolt4  ,we now proceed to notice the    

modern tumbler-lock4 ,this was arranged 
by ,bird1 whose patent1 bearing date    
#bith ,october1 #agij1 was for a series 
of four double-acting tumblers1         
differing in no respect from those      
patented by ,barron1 and closely        
resembling those in use at the present  
time in the best tumbler-locks4 ,we will
 describe the modern tumbler-lock more  
particularly when we have gone through a
 few historical details on the subject4 
,messrs4 ,mitchell and ,lawton obtained 
a patent bearing date #gth ,march1      
#ahae1 for a lock in which were combined
 with the bolt and double-acting        
tumblers1 a series of movable wards1 and
 a revolving curtain for closing the    
key-hole4 ,the action of the wards was  
peculiar4 ,on introducing any key or    
instrument1 and passing it round1 a     
number of movable wards or pieces were  
thrown out so as to prevent the key from
 being turned back or withdrawn4 ,it was
 necessary therefore to pass round the  
key so as to unlock the lock1 and if    

that were not possible1 as in the case  
of a false key being used1 it was held  
permanently1 and could only be released 
by destroying the lock1 ,when the bolt  
was once shot1 the wards were carried up
 so as to leave a clear passage for the 
key4 ,this lock does not appear ever to 
have come into use1 on account of the   
violence required in case a wrong key   
should be used either by accident or    
design4  ,the detention of a wrong key  
in this lock appears to have suggested  
the contrivance of a detector4 ,this was
 first made by ,ruxton1 whose patent is 
dated #adth ,may1 #ahaf4 ,his detectors 
were of various kinds1 the object of    
each kind being to give information to  
the owner in case any one of the        
tumblers should be overlifted in an     
attempt to pick the lock1 which fact    
would be discovered on the next         
application of the true key4 ,this is   
precisely the object of the detector in 
tumbler-locks at the present day1 and   
,ruxton accomplished it by somewhat     

similar means4 ,he also had a           
contrivance for holding a false key1 as 
in ,mitchell and ,lawton's lock2 and he 
recommended this form of detector in the
 following words3 8,it is true that in  
this case the lock will have to be      
destroyed in order to open the door3 the
 result is frightful2 but we think the  
more terrible the result1 the less      
likely would any one be to tamper with  
it40  ,we now come to ,chubb's lock1    
patented #c;d ,february1 #ahah1 which   
consisted of double-acting tumblers and 
a peculiar kind of detector4 ,this lock 
has been made the subject of various    
patents obtained in the years #ahbd1    
#ahcc1 #ahdf1 and #ahdg4 ,this lock#d   
consists of six separate and distinct   
double-acting tumblers1 all of which    
must be raised to a particular height1  
neither more nor less1 in order that the
 bolt may pass4 ,it also comprises a    
detector1 by which1 should any one of   
the tumblers be lifted too high in an   
attempt to pick or open the lock by a   

false key1 it would be immediately      
detected on the next application of the 
proper key4 ,the tumblers are flat      
pieces of iron or steel1 with the plane 
of the surface vertical1 and pivoted at 
one end2 and the following is the mode  
in which the key1 the tumblers1 and the 
bolt1 are brought into mutual action4   
#d ,the lock about to be described is   
the latest and most complete   form of  
,chubb lock up to the date of the ,great
 ,exhibition4 ,the various   additions  
and alterations which have been made in 
the lock since that   date will be      
noticed in a subsequent chapter4  ,the  
bolt shoots in and out of the lock in   
the usual way4 ,it has a square stud or 
stump riveted on one surface2 and it is 
to furnish obstructions to the passage  
of this stud that the tumblers are      
provided4 ,all the six tumblers are     
pivoted to one pin at the end1 giving to
 each of them a small leverage1 each    
independent of the others4 ,there are   
six springs which press these tumblers  

downwards1 one to each tumbler4 ,there  
is a longitudinal slot or gating in each
 tumbler1 large enough to receive the   
stud of the bolt2 and unless all the six
 slots 7supposing there to be six       
tumblers7 coincide in height or         
position1 the stud will not have a clear
 passage for moving to and fro4 ,now the
 slots are purposely made nearer the    
upper edge in some of the tumblers than 
in others1 all the six being different  
in this respect2 so that if they are all
 lifted equally1 the slots do not       
coincide1 and the bolt and its stud will
 not pass4 ,the tumblers must then be   
raised unequally1 those to be most      
raised which have the slot nearest to   
the lower edge4 ,to effect this1 the bit
 of the key is cut into six steps or    
inequalities1 each to act upon one      
particular tumbler1 and each cut or     
stepped to the exact depth which will   
suffice for the proper raising of the   
tumbler4 ,the key is inserted in the    
keyhole1 and is turned2 the six steps   

raise the six tumblers all to the proper
 height1 to leave a clear passage along 
the slots2 and the extreme end of the   
key then acts upon the bolt itself1 and 
shoots it4 ,to unlock it again1 the same
 or a duplicate key must be used2 for if
 another key be employed1 differing by  
ever so little from the proper one1 some
 one or more of the tumblers will be    
lifted either a little too much or not  
quite enough2 and in either case the    
stud of the bolt will catch above or    
below the slot1 instead of having a     
clear line of movement along the slot   
itself4 ,after both locking and         
unlocking1 the springs force the        
tumblers down as far as they can go1    
burying the stud in the recesses above  
the slot2 so that the tumblers must be  
raised by the key both for locking and  
unlocking4  ,the doctrine of chances has
 wide play in determining the relative  
position of the six tumblers4 ,in ,mr4  
,chubb's essay this part of the subject 
is treated in the following way3 8,the  

number of changes which may be effected 
on the keys of a three-inch drawer-lock 
is #a  #b  #c  #d  #e  #f  #gbj1 the    
number of different combinations which  
may be made on the six steps of unequal 
lengths 7on a six-tumbler lock71 without
 altering the length of either step4    
,the height of the shortest step is1    
however1 capable of being reduced #bj   
times2 and each time of being reduced1  
the #gbj combinations may be repeated2  
therefore #gbj  #bj  #ad1djj changes4   
,the same process1 after reducing the   
shortest step as much as possible1 may  
be gone through with each of the other  
five steps2 therefore #ad1djj  #f       
#hf1djj1 which is the number of changes 
that can be produced on the six steps4  
,if1 however1 the seventh step1 which   
throws the bolt1 be taken into account1 
the reduction of it only ten times would
 give #hf1djj  #aj  #hfd1jjj1 as the    
number of changes on locks with the keys
 all of one size 7that is1 with one key 
of definite size in all save the lengths

 of the steps74 ,moreover1 the drill    
pins of the locks and the pipes of the  
keys may be easily made of three        
different sizes2 and the number of      
changes will then be #hfd1jjj  #c       
#b1eib1jjj1 as the whole series of      
changes which may be gone through with  
this key4 ,in smaller keys1 the steps of
 which are capable of being reduced only
 ten times1 and the bolt-step only five 
times1 the number of combinations will  
be #gbj  #aj  #f  #e  #c  #fdh1jjj4 ,on 
the other hand1 in larger keys1 the     
steps of which can be reduced thirty    
times1 and the bolt-step twenty times1  
the total number of combinations will be
 #gbj  #cj  #f  #bj  #c  #g1ggf1jjj40   
,these enormous numbers have been the   
cause of much of the wonderment which   
the six-tumbler locks have excited2 and1
 as we shall see further on1 the ,bramah
 lock presents still more of the        
marvellous in respect to this ringing of
 the changes4  ,illustration3 fig4 #ca4 
,chubb lock1 with detector and six      

tumblers4  ,the construction and action 
of the ,chubb lock may be further       
illustrated by means of an engraving1   
fig4 #ca1 in which b is the bolt of the 
lock1 with a stump riveted to it marked 
s4 ,the six tumblers are shewn          
perspectively1 the front or anterior one
 being marked t2 they all move on the   
centre-pin a1 but are nevertheless      
perfectly distinct and separate1 to     
allow of being elevated to different    
heights4 ,at d is shewn one end of a    
divided spring1 the divisions being     
equal to the number of tumblers1 one to 
each1 and so bent that each spring may  
press upon its particular tumbler4 ,at e
 is the detector-spring1 so placed that 
a projecting piece in the hindmost      
tumbler shall be near it2 this tumbler  
having also fixed into it a stud or pin 
p4 ,this being the arrangement1         
especially in relation to the stump s   
and the tumblers1 it follows that all   
the tumblers must be lifted to exact and
 regulated heights in order that the    

stump may pass through the longitudinal 
slits of the tumblers2 unless it can do 
so1 the bolt cannot be withdrawn4 ,as   
there are gaps or notches in each       
tumbler both above and below the proper 
line of passage1 and as there are no    
ordinary means of ascertaining when any 
one tumbler is lifted too high or not   
high enough1 the safety of the lock is  
greatly increased by this uncertainty2  
especially when it is considered that   
this uncertainty is multiplied sixfold  
by the different modes in which the six 
tumblers are slotted4 ,if1 through the  
insertion of a false key1 or by any     
other cause1 any one of the tumblers be 
raised above its proper position1 the   
detector spring e will catch the        
hindmost tumbler1 and retain it so as to
 prevent the bolt from passing2 and     
thus1 upon the next application of the  
true key1 it will be instantly felt that
 some one of the tumblers has been      
overlifted1 because the true key will   
not unlock it4 ,to relieve the bolt from

 this temporary imprisonment1 the key   
must be turned the reverse way1 as for  
locking2 all the tumblers will thus be  
brought to their proper position1 and   
allow the stump to enter the notches n  
n2 the bevelled part of the bolt will   
then lift up the detector-spring1 and   
allow the hindmost tumbler to fall down 
into its proper place2 and all this     
being effected1 the lock may be opened  
and shut in the ordinary way4 ,the pin p
 is so adjusted that if any one of the  
tumblers--front1 back1 or               
intermediate--be lifted too high1 the   
pin will be lifted with it1 and will    
catch into the detector-spring1 thus    
producing the result just described4    
,illustration3 fig4 #cb4  ,key to       
,chubb's lock4  ,the key is represented 
in fig4 #cb4 ,it has six steps1 besides 
a terminal step to act upon the bolt4   
,the height of each step1 or the        
distance to which it extends from the   
pipe of the key1 depends of course on   
the height to which its corresponding   

tumbler is to be lifted2 and it matters 
not whether the steps of the key are    
adjusted to the slots of the tumblers1  
or the slots to the steps1 provided the 
agreement be brought about4 ,it is      
simply a matter of manufacturing        
convenience that the key-steps are cut  
first and the tumbler-slots afterwards4 
,we may here remark that bit1 or bitt1  
is the name given1 somewhat             
indefinitely1 either to the whole flat  
part of a key1 or to the small stepped  
portions of it4 ,the flat part was      
formerly termed the web of the key1     
probably from the webbed appearance of  
the keys to complex warded locks4       
,after the reading of ,mr4 ,chubb's     
paper before the ,institution of ,civil 
,engineers1 ,mr4 ,owen narrated one or  
two circumstances connected with the    
early history of ,chubb's lock4 ,a      
convict on board one of the prison-ships
 at ,portsmouth dockyard1 who was by    
profession a lock-maker1 and who had    
been employed in ,london in making and  

repairing locks for several years1 and  
subsequently had been notorious for     
picking locks1 asserted that he had     
picked with ease one of the best of     
,bramah's locks1 and that he could pick 
,chubb's locks with equal facility4 ,one
 of the latter was secured by the seals 
of the late ,sir ,george ,grey1 the     
,commissioner1 and some of the principal
 officers of the dockyard1 and given to 
the convict1 together with files and all
 the tools which he stated were         
necessary for preparing false           
instruments for the purpose1 as also    
blank keys to fit the pin of the lock4  
,a lock exactly the same in principle   
was placed in his hands1 that he might  
examine it and make himself master of   
its construction4 ,if he succeeded in   
opening the lock1 he was to receive a   
free pardon from the ,government1 and a 
reward of #ajjl4 from ,messrs4 ,chubb4  
,after trying for two or three months to
 pick the sealed lock--during which     
time1 by his repeated efforts1 he       

frequently over-lifted the detector1    
which was as often re-adjusted for his  
subsequent trials--he gave up the       
attempt4 ,he stated that ,chubb's were  
the most secure locks he had ever met   
with1 and that it was impossible for any
 man to pick or to open them with false 
instruments4  ,mr4 ,owen further stated1
 that in order to compare the merits of 
,bramah's and ,chubb's locks1 he had    
suggested a mechanical contrivance1     
which was applied to one of ,bramah's   
six-spring padlocks belonging to the    
,excise4 ,it was hung upon a nail1 in a 
vertical position1 secure from lateral  
oscillation4 ,a self-acting apparatus   
was then applied1 consisting of a pipe  
with hexagonal grooves1 and a stud or   
bit corresponding with the division of  
the lock1 and secured to it by a spring4
 ,in the grooves of this pipe small     
slides were inserted1 which pressed     
against the spring keys of the lock2 to 
these slides were attached levers1 acted
 upon by eccentrics1 moved by a         

combination of wheels1 whose teeth      
differed in number so as to perform the 
permutation required for the different  
depths of the spring keys1 corresponding
 with those of the proper key to the    
lock4 ,the automaton machine was set in 
motion by a line working over a barrel1 
and acted upon by a weight2 and was thus
 left acting upon the mechanism for a   
considerable time4 ,at right angles to  
the pipe or false key was attached a rod
 and weight2 and when the notches in the
 spring keys were brought in a line with
 the plane of the plate or diaphragm of 
the lock1 the rod and weight turned the 
false key1 opened the lock1 and stopped 
the further motion of the automaton4 ,in
 that state the slides indicated the    
exact depth of the grooves in the proper
 key1 and gave the form of a matrix by  
which to make a key similar to the      
original one4 ,the automaton worked     
during a period varying from half an    
hour to three hours1 according to the   
state of permutation of the apparatus at

 the moment of being applied1 compared  
with that of the slides in the lock4 ,we
 confess that it is difficult to        
understand the action of this automaton 
from ,mr4 ,owen's description4 ,we      
imagine that the false notches would    
effectually prevent the operation of the
 instrument1 and openings would be      
required on each slide to bring it back1
 so as to meet the motions of the       
machine4  ,mr4 ,owen did not state      
whether his apparatus had been          
successful with one only of ,bramah's   
locks or with several2 nor did he       
describe any apparatus invented with the
 view to the picking of ,chubb's locks4 
,he stated1 however1 that in order to   
ascertain the effect of friction on one 
of these last-named locks1 it was       
subjected to the alternate rectilinear  
motion of a steam-engine in ,portsmouth 
dockyard1 and was locked and unlocked   
upwards of #dfj1jjj times consecutively1
 without any appreciable wear being     
indicated by a gauge applied to the     

levers and the key1 both before and     
after this alternate action4 ,mr4 ,owen 
concluded by expressing his individual  
opinion that ,chubb's lock had never    
been picked4 8,the detector was the main
 feature of its excellence2 and         
additional precaution1 therefore1 was   
only departing from its simplicity1 and 
adding to the expense1 without any      
commensurate advantage40  ,in a         
subsequent chapter the degree of        
security afforded by various            
descriptions of locks1 and the obstacles
 which they present of being picked1    
will come under notice2 we therefore now
 proceed to describe briefly a few other
 tumbler-locks1 or application of the   
tumbler-principle4  ,in ,mr4            
,somerford's lock1 for which the        
,society of ,arts gave a premium in     
#ahah1 an attempt was made to improve   
upon the ordinary action of tumblers4   
,in most such locks1 all the tumblers   
must ascend1 although to different      
heights1 before the stud of the bolt can

 pass through the slots2 8which         
arrangement10 says ,mr4 ,somerford1     
8gives an opportunity of introducing a  
nail1 or a piece of stout wire1 into the
 lock1 and thus raising the tumblers    
without the necessity of using the key40
 ,in his new lock1 however1 he made one 
lever to ascend while the other         
descended1 by a somewhat complicated    
arrangement of slotted plates above and 
below the bolt4 ,the key was so         
perforated as to be much endangered in  
respect to strength4  ,in ,davis's lock 
there is a double chamber with wards on 
the side of the key-hole4 ,the key is   
inserted into the first chamber and     
turned a quarter round2 it is then      
pushed forward into the inner chamber1  
where there is a rotating plate         
containing a series of small pins or    
studs1 which are laid hold of by the    
key4 ,by turning the key1 the plate is  
moved round1 the tumbler is raised1 and 
the bolt is shot backwards and forwards4
 ,this lock1 which is somewhat          

expensive1 is used to some extent on    
,cabinet despatch-boxes4  ,the lock     
invented by ,mr4 ,nettlefold is so      
constructed1 that when the bolt is shot 
out by the key1 two teeth or quadrants  
are projected from the sides of the     
bolt1 which take a firm hold of the     
plate fixed on the door-post or edge4   
,this construction is said to answer    
well for sliding-doors4  ,mr4 ,alfred   
,ainger1 in #ahbj1 received a silver    
medal from the ,society of ,arts for a  
draw-back spring latch1 in which the    
objects proposed were the two           
following--to render the lock more      
difficult of violation by a pick than   
those ordinarily in use2 and to apply to
 it a key of which no ordinary person   
could take an impress1 and which would  
be difficult of access even in a        
workman's hand4 ,the key is very        
peculiar2 its pipe consists of three    
divisions1 the section of the upper and 
lower divisions being circular1 and that
 of the middle division triangular2 the 

triangular portion is intended to give  
motion to some part of the interior of  
the lock during the rotation of the key4
 ,there are collars fixed on the        
extremity of the key1 to act each on one
 tumbler2 and there are modes1 by       
varying the arrangement of these collars
 on an octagonal stem1 to give something
 like a permutation to the number of    
variations to which the action of the   
key may be subject4 ,the notches or     
slots are rather in the bolt than in the
 tumblers2 and there are many           
peculiarities in the general            
arrangement4  ,in a lock invented and   
patented by ,mr4 ,parsons1 the tumblers 
are of a particular form1 being hinged  
on a pivot at their centres1 and working
 into and out of two notches cut in the 
under side of the bolt4 ,it must be     
obvious that many variations in the     
adjustment of the tumblers of locks     
might be made1 without vitiating the    
principle on which the action depends4  
,many inventors have tried the use of an

 expanding web to the key1 so planned   
that if the step of the web be long     
enough to reach the tumbler1 it would be
 too long to pass through the key-hole2 
and therefore a principle of safety     
would operate by enabling the key to    
adjust itself at one moment to the size 
of the key-hole1 and at another to the  
height of the tumbler4 ,mr4 ,machin of  
,wolverhampton invented such a key in   
#ahbg4 ,the web of the key is movable on
 a countersunk pin1 on which it can so  
far slide as to be drawn one-eighth of  
an inch from the barrel4 ,the key-hole  
is of such a size as to admit the key   
only when the web is pressed close up to
 the barrel4 ,when the key in this state
 is introduced1 and is begun to be      
turned round1 one of the notches in the 
web works into a raised circular edge of
 steel1 placed eccentrically with regard
 to the lock-pin2 so that as the key is 
turned1 the web becomes drawn out1 and  
is at its greatest elongation when it   
arrives at the tumblers3 in the second  

half of its circular movement1 the key  
becomes contracted to its original      
dimensions1 and can then be removed from
 the lock4  ,another mode of modifying  
the key has been introduced by ,mr4     
,mackinnon1 the object being to enable  
any person to change at will the pattern
 or arrangement of the movable parts of 
a lock and key2 or to keep the key1 when
 not actually in use1 in such a state as
 to render it unavailing to any one but 
himself4 ,it was a complex arrangement1 
which does not seem to have come much   
into use4  ,the lock invented by ,mr4   
,williams1 in #ahci1 may be designated a
 pin-lock1 involving a principle        
analogous in many points to that of the 
,egyptian lock4 ,this lock has a series 
of pins which reach through the cap1 and
 are pressed to their places with a key 
like a comb or a rake-head4 ,on the     
inner end of each pin is a flat piece of
 steel1 in which is cut a notch for the 
passage of the bolt2 but this passage is
 not clear until the notches in all the 

pieces of steel are in a right line4    
,the pins are movable1 and can be pushed
 either too far or not far enough to    
bring about the coincidence of position 
in the notches2 and on this ground they 
are 8double-acting40 ,now the teeth of  
the key are of irregular lengths1 each  
having a length just suited for pushing 
the pin to the proper depth3 any other  
lengths of teeth would fail to open the 
lock4 ,there is a mechanism of springs  
and levers to shoot the bolt when the   
pins in the plate are rightly adjusted4 
,the arrangements in respect to the key 
are singular and somewhat awkward4 ,the 
teeth which lock the bolt are not the   
same as those which unlock it1 the user 
having to change ends and adjust the bit
 to a socket-handle4 ,this is one among 
many examples in which a lock embodies  
several principles1 the inventor having 
set himself the task of combining the   
excellences of many diverse locks4  ,in 
respect to the tumbler-locks generally1 
the simplicity of action1 the strength  

of construction1 and the non-liability  
of disarrangement1 have given them a    
high place among safety-locks4 ,the only
 danger seemed to be1 that any person   
once obtaining possession of the key    
could take an impression from it1 and   
thence form a key which would command   
the lock4 ,attempts have been           
occasionally made to obviate this       
danger1 by supplying the key with       
movable bits which could be changed at  
pleasure1 so as to constitute any number
 of effectively different bits in       
succession4 ,but the locks being so     
constructed that the bolt could only be 
moved when the tumblers were in a       
certain position1 the owner was placed  
in this predicament3 that it was useless
 to alter the arrangement of the bits in
 the key1 unless the tumblers were      
altered in a corresponding manner2 and  
this would entail the removal of the    
lock from the door1 and the             
re-arrangement of the interior          
mechanism4  ,one of the great defects of

 tumbler-locks made previously to the   
last ten years was1 that the tumblers1  
when lying at rest in the lock1         
presented at their bellies or lower     
edges precisely the same arrangement as 
the steps of the key4 ,indeed1 in many  
locks of the present day1 a good idea of
 the form of the key may be gained by   
feeling the bellies of the tumblers4    
,the bellies are in fact cut out so as  
to compensate for the circular motion of
 the key1 to allow them to remain at    
rest while the stump is passing through 
the gating4 ,even in tumbler-locks of   
the best construction the tumblers will 
vibrate more or less during the motion  
of the key2 a defect which must be      
provided against in adjusting the lock1 
or the stump will be caught in its      
passage through the gating4 ,mr4 ,hobbs 
provides a simple remedy by enlarging   
the back part of the gating1 the effect 
of which is as follows3 when1 in        
shooting back the bolt1 as in unlocking1
 the key has got to its highest point1  

the stump enters the narrow end of the  
gating2 but in shooting the bolt        
forward1 as in locking1 the stump enters
 the gating before the key has got to   
its highest point1 and to allow for the 
slight vibratory motion of the tumblers 
during the passage of the stump1 the    
gating is widened4 ,the usual method of 
adjustment is to alter the forms of the 
bellies of the tumblers1 thus greatly   
risking the security of the lock1 a     
defect which was clearly perceived by   
,bramah see pp4 #fg-gj1 and was one of  
the reasons which induced him to        
construct locks with slides instead of  
tumblers4  ,american locks on the       
tumbler-principle1 and the relation     
which all such locks bear to the ,bramah
 lock1 will be better understood after  
the details of the following chapter4   
,,chapter ,,vi4  ,,the ,,bramah ,,lock4 
,the lock which was invented by the late
 ,mr4 ,bramah deservedly occupies a high
 place among this class of contrivances4
 ,it differs very materially from all   

which has gone before it2 its mechanical
 construction is accurate and beautiful2
 its key is remarkable for smallness of 
size2 and the invention was introduced  
by the publication of an essay          
containing much sensible observation on 
locks generally4 ,the full title of this
 essay runs thus3 8,a dissertation on   
the ,construction of ,locks4            
,containing1 first1 reasons and         
observations1 demonstrating all locks   
which depend upon fixed wards to be     
erroneous in principle1 and defective in
 point of security4 ,secondly1 a        
specification of a lock1 constructed on 
a new and infallible principle1 which1  
possessing all the properties essential 
to security1 will prevent the most      
ruinous consequences of house-robberies1
 and be a certain protection against    
thieves of all descriptions40 ,a second 
edition of this ,dissertation was       
published in #ahae2 but the work is now 
extremely scarce1 and hardly attainable4
  ,it is remarkable to observe the      

boldness and self-relying confidence    
with which ,mr4 ,bramah1 some sixty     
years ago1 declared that all locks were1
 up to that time1 violable2 he felt that
 this was strictly true1 and he         
hesitated not to give expression to his 
conviction4 ,the following is from his  
,dissertation3--  8,it is observable    
that those who are taken in the         
desperate occupation of house-breaking  
are always furnished with a number and  
variety of keys or other instruments    
adapted to the purpose of picking or    
opening locks2 and it needs no argument 
to prove that these implements must be  
essential to the execution of their     
intentions4 ,for unless they can secure 
access to the portable and most valuable
 part of the effects1 which in most     
families are deposited under the        
imaginary security of locks1 the plunder
 would seldom recompense the difficulty 
and hazard of the enterprise2 and till  
some method of security be adopted by   
which such keys and instruments may be  

rendered useless1 no effectual check or 
opposition can be given to the excessive
 and alarming practice of               
house-breaking4  8,being confident that 
,i have contrived a security which no   
instrument but its proper key can reach2
 and which may be so applied as not only
 to defy the art and ingenuity of the   
most skilful workman1 but to render the 
utmost force ineffectual1 and thereby to
 secure what is most valued as well from
 dishonest servants as from the midnight
 ruffian1 ,i think myself at liberty to 
declare 7what nothing but the discovery 
of an infallible remedy would justify my
 disclosing71 that all dependence on the
 inviolable security of locks1 even of  
those which are constructed on the best 
principle of any in general use1 is     
fallacious4 ,to demonstrate this bold   
and alarming proposition1 ,i shall first
 state the common principles which are  
applied in the art of lock-making2 and  
by describing their operation in        
instruments differently constructed1    

prove to my intelligent readers that the
 best-constructed locks are liable to be
 secretly opened with great facility2   
and that the locks in common use are    
calculated only to induce a false       
confidence in their effect1 and to throw
 temptation to dishonesty in the way of 
those who are acquainted with their     
imperfections1 and know their inefficacy
 to the purpose of security0 7p4 #e74   
,tumblers had been so little thought of 
and used at the time ,bramah wrote1 that
 his attention was almost exclusively   
directed to warded locks4 ,the          
mysterious clefts in a key1 connected   
with some kind of secret mechanism in   
the lock1 had given the warded locks a  
great hold on the public mind1 as models
 of puzzlement and security2 and it was 
to shew that this confidence rested on a
 false basis1 that he to a great extent 
laboured4 ,the following is his         
exposition of the principle and the     
defects of the warded lock4  8,locks    
have been constructed1 and are at       

present much used and held in great     
esteem1 from which the picklock is      
effectually excluded2 but the admission 
of false keys is an imperfection for    
which no locksmith has ever found a     
corrective2 nor can this imperfection be
 remedied whilst the protection of the  
bolt is wholly confided to fixed wards4 
,for if a lock of any given size be     
furnished with wards in as curious and  
complete a manner as it can be1 those   
wards being necessarily expressed on    
what is termed by locksmiths the bit or 
web of the key1 do not admit of a       
greater number of variations than can be
 expressed on that bit or web2 when1    
therefore1 as many locks have been      
completed of the given size as will     
include all the variations which the    
surface of the bit will contain1 every  
future lock must be the counterpart of  
some former one1 and the same key which 
opens the one will of course unlock the 
other4 ,it hence follows that every lock
 which shall be fabricated on this given

 scale1 beyond the number at which the  
capability of variation ends1 must be as
 subject to the key of some other lock  
as to its own2 and both become less     
secure as their counterparts become more
 numerous4 ,this objection is confirmed 
by a reference to the locks commonly    
fixed on drawers and bureaus1 in which  
the variations are few1 and these so    
frequently repeated1 from the infinite  
demand for such locks1 that1 even if it 
were formed to resist the picklock1 they
 would be liable to be opened by ten    
thousand correspondent keys4 ,and the   
same observation applies in a greater or
 less degree to every lock in which the 
variations are not endless4  8,but if   
the variation of locks in which the bolt
 is guarded only by fixed wards could be
 multiplied to infinity1 they would     
afford no security against the efforts  
of an ingenious locksmith2 for though an
 artful and judicious arrangement of the
 wards1 or other impediments1 may render
 the passage to the bolt so intricate   

and perplexed as to exclude every       
instrument but its proper key1 a skilful
 workman having access to the entrance  
will be at no loss to fabricate a key   
which shall tally as perfectly with the 
wards as if the lock had been open to   
his inspection4 ,and this operation may 
not only be performed to the highest    
degree of certainty and exactness1 but  
is conducted likewise with the utmost   
ease4 ,for the block or bit1 which is   
intended to receive the impression of   
the wards1 being fitted to the keyhole1 
and the shank of the key bored to a     
sufficient depth to receive the pipe1   
nothing remains but to cover the bit    
with a preparation which1 by a gentle   
pressure against the introductory ward1 
may receive its impression1 and thus    
furnish a certain direction for the     
application of the file4 ,the block or  
bit being thus prepared with a tally to 
the first ward1 gains admission to the  
second2 and a repetition of the means by
 which the first impression was         

obtained1 enables the workman to        
proceed1 till by the dexterous use of   
his file he has effected a free passage 
to the bolt4 ,and in this operation he  
is directed by an infallible guide2 for1
 the pipe being a fixed centre on which 
the key revolves without any variation1 
and the wards being fixed likewise1     
their position must be accurately       
described on the surface of the bit     
which is prepared to receive their      
impression4 ,the key therefore may be   
formed and perfectly fitted to the lock 
without any extraordinary degree of     
genius or mechanical skill4 ,it is from 
hence evident that endless variations in
 the disposition of fixed wards are not 
alone sufficient to the purpose of      
perfect security4 ,i do not mean to     
subtract from the merit of such         
inventions1 nor to dispute their utility
 or importance4 ,every approach towards 
perfection in the art of lock-making may
 be productive of much good1 and is at  
least deserving of commendation2 for if 

no higher benefit were to result from   
it1 than the rendering difficult or     
impossible to many that which is still  
practicable and easy to a few1 it       
furnishes a material security against   
those from whom the greatest mischiefs  
and dangers are to be apprehended40     
,there can be little doubt1 in the      
present day1 that ,bramah did not       
over-rate the fallacies embodied in the 
system of wards for locks4 ,he was      
sufficiently a machinist to detect the  
weak points in the ordinary locks2 and1 
whatever may have been his over-estimate
 of his own lock 7presently to be       
described71 he was certainly guilty of  
no injustice to those who had preceded  
him2 for their locks were substantially 
as he has described them4 ,to understand
 the true bearings of his ,dissertation 
too1 we must remember that housebreaking
 had risen to a most daring height in   
,london at the time he wrote 7about the 
middle of the reign of ,george ,,iii472 
and men's minds were more than usually  

absorbed by considerations relating to  
their doors and locks4  ,mr4 ,bramah1   
after doing due justice to the ingenuity
 of ,barron's lock1 in which1 if the    
tumbler be either over lifted or under  
lifted the lock cannot be opened1       
pointed out very clearly the defective  
principle which still governed the lock4
 8,greatly as the art is indebted to the
 ingenuity of ,mr4 ,barron1 he has not  
yet attained that point of excellence in
 the construction of his lock which is  
essential to perfect security4 ,his     
improvement has greatly increased the   
difficulty but not precluded the        
possibility of opening his lock by a key
 made and obtained as above described   
7by a wax impression on a blank key72   
for an impression of the tumblers may be
 taken by the same method1 and the key  
be made to act upon them as accurately  
as it may be made to tally with the     
wards4 ,nor will the practicability of  
obtaining such a key be prevented1      
however complicated the principle or    

construction of the lock may be1 whilst 
the disposition of its parts may be     
ascertained and their impression        
correctly taken from without4 ,i        
apprehend the use of additional tumblers
 to have been applied by ,mr4 ,barron as
 a remedy for this imperfection40 ,mr4  
,bramah thought that ,barron had a      
perception of a higher degree of        
security1 but had failed to realise it2 
because1 by giving a uniform motion to  
the tumblers1 and presenting them with a
 face which tallies exactly with the    
key1 they still partake in a very great 
degree of the nature of fixed wards1 and
 the security of the lock is thereby    
rendered in a proportionate degree      
defective and liable to doubt4  ,to shew
 how this insecurity arises1 ,mr4       
,bramah illustrates the matter in the   
following way3 8,suppose the key with   
which the workman is making his way to  
the bolt to have passed the wards1 and  
to be in contact with the most prominent
 of the tumblers4 ,the impression1 which

 the slightest touch will leave on the  
key1 will direct the application of the 
file till sufficient space is prepared  
to give it a free passage4 ,this being  
accomplished1 the key will of course    
bear upon the tumbler which is most     
remote2 and being formed by this process
 to tally with the face which the       
tumblers present1 will acquire as       
perfect a command of the lock as if it  
had been originally made for the        
purpose4 ,and the key1 being thus       
brought to a bearing on all the tumblers
 at once1 the benefit arising from the  
increase of their number1 if multiplied 
by fifty1 must inevitably be lost2 for1 
having but one motion1 they act only    
with the effect of one instrument40  ,it
 is worthy of notice1 that even while   
thus shewing the weak points of the     
,barron lock1 ,mr4 ,bramah seems to have
 had in his mind some conception of     
infallibility or inviolability          
attainable by the lock in question4     
,after speaking of the defect arising   

from the bad arrangement of the         
tumblers1 he says3 8,but nothing is more
 easy than to remove this objection1 and
 to obtain perfect security from the    
application of ,mr4 ,barron's principle4
 ,if the tumblers1 which project        
unequally and form a fixed tally to the 
key1 were made to present a plane       
surface1 it would require a separate and
 unequal motion to disengage them from  
the bolt2 and consequently no impression
 could be obtained from without that    
would give any idea of their positions  
with respect to each other1 or be of any
 use even to the most skilful and       
experienced workman in the formation of 
a false key4 ,the correction of this    
defect would rescue the principle of    
,mr4 ,barron's lock1 as far as ,i am    
capable of judging1 from every          
imputation of error or imperfection2    
and1 as long as it could be kept        
unimpaired1 would be a perfect security4
 ,but the tumblers1 on which its        
security depends1 being of slight       

substance1 exposed to perpetual         
friction--as well from the application  
of the key as from their own proper     
motion--and their office being such as  
to render the most trifling loss of     
metal fatal to their operation1 they    
would need a further exertion of ,mr4   
,barron's ingenuity to make them        
durable40  ,it may perhaps be doubted   
whether the principle of ,bramah's lock 
is not more clearly shewn in the        
original constructed by him than in that
 of later date4 ,in appearance it is    
totally different1 but the same         
pervading principle is observable in    
both2 and the cylinder lock can         
certainly be better understood when this
 original flat lock has been studied4   
,the annexed woodcut is taken from the  
first and very scarce edition of ,mr4   
,bramah's ,dissertation2 the description
 is somewhat more condensed1 but perhaps
 sufficient for the purpose4            
,illustration3 fig4 #cc4 ,bramah's first
 model4  ,the lock is supposed to be    

lying flat1 with the bolt ,b half-shot4 
,ranged somewhat diagonally are six     
levers1 turning on a horizontal joint or
 pivot at ,a1 each lever having a slight
 extent of vertical motion independent  
of the others4 ,each lever rests on a   
separate spring of sufficient strength  
to sustain its weight1 or1 if depressed 
by a superior force1 to restore it to   
its proper position when the force is   
withdrawn4 ,f is a curved piece of      
metal1 pierced with six grooves or      
passages2 these grooves are exactly     
equal in width to the thickness of the  
levers1 but are of sufficient depth to  
allow the levers a free motion in a     
perpendicular direction4 ,the ends of   
the levers are inserted in these        
grooves1 and have this freedom of       
motion1 whether lifted by the elastic   
power of the springs or depressed by a  
weight from above4 ,in the bolt ,b is a 
notch to receive a peculiarly-shaped    
lever1 which shoots or withdraws the    
bolt according as it traverses to the   

right or the left4 ,this lever1 the six 
long levers1 the springs beneath them1  
the bent piece ,f1 and the pivot1 all   
alike are fixed to a circular platform  
,p1 which turns on a centre2 so that if 
any force can make this platform turn   
partially round1 the bolt must be shot  
or unshot by the lever which works in   
the notch4 ,the six long levers are the 
contrivances whereby the platform shall 
not be allowed to turn until the proper 
moving agent 7the key7 shall have been  
applied1 the plate p being one of the   
assistants in this obstruction4 ,this   
plate1 which is hollow underneath1 has  
six notches in one of its edges2 the    
points of the levers catch into these   
notches2 and while so caught1 the levers
 cannot move horizontally1 and all the  
machinery is at a stand-still4 ,to      
enable the key to set the mechanism in  
action1 other contrivances are          
necessary4 ,each lever has a notch at   
its extreme end1 and the six are notched
 very irregularly in respect one to     

another4 ,these notches must be brought 
all into one plane1 to enable the levers
 to pass horizontally out of the notches
 in the plate1 in the same way as the   
two prongs of a fork might traverse one 
above and the other below the blade of a
 knife2 and when the lever-notches are  
in this position1 all in one plane and  
in the plane of the plate1 the levers   
can be moved1 and with it the stump     
which shoots the bolt4 ,to ensure this  
due pressing down of the levers1 a key  
is used such as is shewn in the cut1    
having six steps or bits to correspond  
with the six levers2 this key1 put upon 
the pin ,k1 presses down all the levers 
to the exact distance necessary for     
bringing their notches into one plane1  
viz4 the plane of the plate2 the key    
then being turned round turns the       
movable platform ,p1 and shoots the     
bolt4 ,it is evident at a glance1 that  
unless the various steps of the key are 
so cut1 that each shall press down its  
own lever to the proper extent1 the ends

 of the levers cannot pass the notches  
in the plate1 and the bolt can neither  
be locked nor unlocked4  ,it may be well
 to give ,bramah's own words in relation
 to this lock3 8,i may safely assert    
that it is not in art to produce a key  
or other instrument by which a lock     
constructed on this principle can be    
opened4 ,it will be a task1 indeed1 of  
great difficulty1 even to a skilful     
workman1 to fit a key to this species of
 lock1 though its interior face were    
open to his inspection2 for the levers  
being raised by the subjacent springs to
 an equal height present a plane        
surface1 and consequently convey no     
direction that can be of any use in     
forming a tally to the irregular surface
 which they present when acting in      
subjection to the proper key4 ,unless1  
therefore1 a method be contrived to     
bring the notches on the ends of the    
levers in a direct line with each other1
 and to retain them in that position    
till an exact impression of the         

irregular surface which the levers will 
then exhibit can be taken1 the workman  
will in vain attempt to fit a key to the
 lock1 or by any effort of art to move  
the bolt4 ,and when it is considered    
that this process will be greatly       
impeded1 and may perhaps be entirely    
frustrated1 by the action of the        
springs1 it must appear that great      
patience and perseverance1 as well as   
great ingenuity1 will be required to    
give any chance of succeeding in the    
attempt4 ,i do not state this           
circumstance as a point essential or of 
any importance to the purpose of the    
lock1 but to prove more clearly what ,i 
have before observed upon its principle 
and properties2 for if such difficulties
 occur to a skilled workman1 as to      
render it almost1 if not altogether     
impracticable to form a key when the    
lock is open to his inspection and its  
parts accessible to his hand1 it pretty 
clearly demonstrates the impossibility  
of accomplishing it when no part of the 

movement can be touched or seen40  ,it  
is evident that ,mr4 ,bramah had his    
thoughts directed to that mode of       
picking locks which depends on taking   
impressions of the moving parts1 rather 
than to the mechanical or pressure      
method which has been developed in later
 times4 ,there can be little doubt that 
a lock was1 to his mind1 a beautiful and
 admirable machine1 far elevated above  
the level of mere blacksmith's work2 and
 his name will ever be associated with  
what may be termed the philosophy of    
lock-making4  ,after the model-lock1    
which has just been described1 was      
constructed1 and found to corroborate   
the idea which was working in ,mr4      
,bramah's mind1 he proceeded to the     
construction of his barrel or           
cylinder-lock1 embracing similar        
elements placed in more convenient      
juxta-position4 ,in his ,essay he gives 
an engraving to illustrate the principle
 on which his lock acts1 rather in the  
manner of a diagram than as depicting   

any lock actually made2 his main object 
being to impart a clear notion of the   
action of the slides which form such a  
distinguishing feature in his lock4     
,illustration3 fig4 #cd4 ,diagram to    
illustrate the ,bramah lock4  ,viewed in
 this sense1 therefore1 simply as an    
illustrative diagram1 the annexed cut   
may represent the action of the safety  
slides4 ,b is a sliding bar or bolt1    
having a power of longitudinal motion in
 the frame ,f4 ,this frame has six      
notches cut on each of its long sides1  
the two series being exactly opposite   
each other2 and there are six similar   
notches cut in the bolt ,b4 ,the        
concurrent effect of all these eighteen 
notches is1 that the six slides a b c d 
e f can move freely up and down across  
the bolt4 ,when the slides are thus     
placed1 the bolt cannot move1 and may in
 this case be considered to be locked4  
,there are six clefts or notches in the 
six slides1 one to each 7#a1 #b1 #c1 #d1
 #e1 #f72 and until all these are       

brought in a right line1 the bolt cannot
 move through them4 ,if a tally or key  
be prepared1 as shewn at ,t in the lower
 part of the cut1 with six projections1 
and if these projections thrust up the  
six slides till their clefts rise to the
 plane of the bolt1 then can the bolt be
 withdrawn or the lock opened4 ,this    
serves to illustrate the relation       
between the slides and the key1 as      
carried out in the way now to be        
described4  ,one peculiarity of the     
,bramah lock is1 that from the essential
 part of the apparatus being a barrel or
 cylinder1 much of the working can be   
conducted in the lathe2 and this has    
given a beauty to the details generally 
and deservedly admired4 ,mr4 ,bramah1   
when he worked out the theory of his    
lock1 resolved to discard altogether the
 use of fixed wards1 and also the use of
 tumblers working on a pivot at one end2
 substituting in their stead a system of
 slides1 working in a very novel way4   
,the body of a ,bramah lock may be      

considered as formed of two concentric  
brass barrels1 the outer one fixed1 and 
the inner rotating within it4 ,the inner
 barrel has a projecting stud1 which1   
while the barrel is rotating1 comes in  
contact with the bolt in such a way as  
to shoot or lock it2 and thus the stud  
serves the same purpose as the bit of an
 ordinary key1 rendering the            
construction of a bit to the ,bramah key
 unnecessary4 ,if the barrel can be made
 to rotate to the right or left1 the    
bolt can be locked or unlocked2 and the 
problem is1 therefore1 how to ensure the
 rotation of the barrel4 ,the key1 which
 has a pipe or hollow shaft1 is inserted
 in the keyhole upon the pin1 and is    
then turned round2 but there must be a  
very nice adjustment of the mechanism of
 the barrel before this turning round of
 the key and the barrel can be ensured4 
,the barrel has an external circular    
groove at right angles to the axis1     
penetrating to a certain depth2 and it  
has also several internal longitudinal  

grooves1 from end to end4 ,in these     
internal grooves thin pieces of steel   
are able to slide1 in a direction       
parallel with the axis of the barrel4 ,a
 thin plate of steel1 called the        
locking-plate1 is screwed in two        
portions to the outer barrel1 concentric
 with the inner barrel2 and at the same 
time occupying the external circular    
groove of the inner barrel2 this plate  
has notches1 fitted in number and size  
to receive the edges of the slides which
 work in the internal longitudinal      
grooves of the barrel4 ,if this were    
all1 the barrel could not revolve1      
because the slides are catching in the  
grooves of the locking-plate2 but each  
slide has also a groove1 corresponding  
in depth to the extent of this          
entanglement2 and if this groove be     
brought to the plane of the             
locking-plate1 the barrel can be turned1
 so far as respects that individual     
slide4 ,all the slides must1 however1 be
 so adjusted that their grooves shall   

come to the same plane2 but as the notch
 is cut at different points in the      
lengths of the several slides1 the      
slides have to be pushed in to different
 distances in the barrel1 in order that 
this juxta-position of notches may be   
ensured4 ,this is effected by the key1  
which has notches or clefts at the end  
of the pipe equal in number to the      
slides1 and made to fit the ends of the 
slides when the key is inserted2 the key
 presses each slide1 and pushes it so   
far as the depth of its cleft will      
permit2 and all these depths are such   
that all the slides are pushed to the   
exact position where their notches all  
lie in the same plane2 this is the plane
 of the locking-plate1 and the barrel   
can be then turned4  ,illustration3 fig4
 #ce4 ,exterior of a ,bramah lock4      
,this is the principle which ,mr4       
,bramah adopted2 and we have now to     
trace it1 step by step1 by means of     
illustrative details4 ,fig4 #ce         
represents the exterior of a box or desk

 lock1 one among many varieties which   
the ,bramah lock presents4 ,a ,a shews  
the bolt1 formed something like two     
hooks rising out of a bar of metal1     
which bar has a backward and forward    
motion upon the plate ,b ,b4 ,the upper 
edge of this plate is turned over at    
right angles1 forming a small horizontal
 surface through which two openings are 
cut to receive the two hooked portions  
of the bolt4 ,the movements of the bolt 
are otherwise guided by the edges of    
square holes through which it works2 the
 holes being made in the edge-pieces of 
the lock1 riveted to the main plate4    
,the bolt is further prevented from     
rising out of its place by means of a   
plate of metal ,c1 which is secured to  
the edge-pieces by two screws #a1 #a1   
and by two steadying pieces4 ,this plate
 has on its surface a cylindrical       
projection ,d1 which contains in effect 
all the working mechanism of the lock4  
,the pins #d #d are employed for        
securing a plate1 which we shall have to

 describe presently4 ,when such a lock  
is fixed upon a desk or box1 the portion
 ,d projects to a small distance through
 a hole in the wood-work1 forming in    
itself a very neat escutcheon1 with a   
key-hole in the centre4  ,illustration3 
fig4 #cf4 ,details of the ,bramah lock4 
,illustration3 fig4 #cg4 ,the slides4   
,so much for the exterior4 ,we must now 
proceed to examine the interior of the  
lock1 especially the part contained     
within the cylinder4 ,in fig4 #cf1 for  
convenience of arrangement1 the several 
parts are exhibited separately1 and as  
if the plane of the lock were           
horizontal1 with the key acting         
vertically4 ,the essential part of the  
mechanism is a barrel or cylinder ,e1   
pierced or bored with a cylindrical hole
 down its centre4 ,the inside of the    
bore has six narrow grooves1 cut        
parallel with the axis1 and in the      
direction of radii2 the grooves are not 
cut through the thickness of the        
cylinder1 but leave sufficient substance

 of metal for strength4 ,in every groove
 is fitted a steel slide of peculiar    
form1 such as is shewn at a a in fig4   
#cg4 ,each slide is split in its        
thickness 7seen in section71 so that it 
may move up and down in its groove with 
a slight friction1 and thereby not fall 
simply by its own weight4 ,each slide   
has three small notches 7#c1 #b1 #c71   
the use of which will presently appear4 
,reverting to fig4 #cf1 the lower part  
of the opening through the cylinder ,e  
is closed by a circular plate of metal1 
fixed to it by two screws2 this plate is
 represented at ,f1 in the lower part of
 the figure4 ,this plate has a vertical 
pin rising from its centre 7also seen at
 b1 fig4 #ci71 and serving as a key-pin 
on which the pipe of the key may work or
 slide2 and it has also a short circular
 stud c projecting from its under side1 
and fitted to enter into a curved       
opening in the bolt presently to be     
described4  ,the point to be now borne  
in mind is this1 that if the cylinder ,e

 turns round1 the plate ,f will also    
turn round1 and with it the stud c2 and 
as this stud works into the peculiarly  
formed cavity d in a portion of the bolt
 7fig4 #ch71 it causes the bolt to be   
shot backwards or forwards4 ,now1 in    
order to prevent this rotating of the   
cylinder unless the proper key be       
employed1 the following mechanism is    
introduced3 the cylinder has a groove   
cut round its circumference at e e1     
extending sufficiently near to the      
internal bore to produce the desired    
effect without too much weakening the   
metal4 ,into this notch is introduced   
the thin circular plate of metal f f1 it
 being divided into two halves for this 
purpose2 and when so placed1 it occupies
 the position shewn by the dotted       
portion e e4 ,when this plate is screwed
 to the case of the lock by the screws  
#d1 #d1 it cannot of course turn round2 
but the cylinder itself will or will not
 turn round according to the position of
 the slides4 ,the plate f f has six     

notches1 #e1 #e1 #e1 c4 in the inner    
edge or circle2 so adjusted that1 when  
the plate is in its place1 the slides a 
a can move up and down4 ,the cylinder   
cannot move round in a circle without   
carrying the slides with it2 and these  
cannot so move unless they are all      
depressed to such exact distances in    
their respective grooves1 that the deep 
notch of each slider 7shewn at #b in    
fig4 #cg7 shall come into the plane of  
the circular plate3 when all are so     
brought1 the cylinder can be turned4 ,if
 any one of the slides be pressed down  
either too low or not low enough1 this  
turning of the cylinder cannot be       
effected1 because the slides will be    
intersected by the edges of the notches 
#e1 #e2 and it is the office of the key1
 therefore1 to press all the six slides 
down to the exact distances required4   
,when the slides are not pressed upon by
 the key1 they are forced upwards to the
 top of the cylinder by a spiral spring 
#f1 coiled loosely round the pin b2 this

 pressure forces up a small collet1 #g1 
on which the upper part of the slides   
rest by a sort of step4  ,illustration3 
fig4 #ch4 ,the bolt4  ,the first locks  
were made with a separate and           
independent spring to each slide2 but it
 is a very great improvement1 the       
introduction of one common spring to    
raise up the whole number2 because if a 
person attempts to pick the lock by     
depressing the slides separately by     
means of any small pointed instruments1 
and by chance brings two or more of them
 to the proper depth for turning round1 
should he press any one too low1 it is  
difficult to raise it again without     
relieving the spring #f1 which          
immediately throws the whole number of  
slides up to the top1 and destroys all  
that had been done towards picking the  
lock4 ,another improvement of this lock1
 and one which very much increased the  
difficulty of picking1 and its          
consequent security1 was the            
introduction of false and deceptive     

notches cut in the sliders1 as seen at  
#c1 #c4 ,it was found that in the       
attempt to pick this lock1 an instrument
 was introduced by the keyhole to force 
the cylinder round4 ,at the same time   
that the slides were depressed by       
separate instruments1 those slides which
 were not at the proper level for moving
 round were held fast by the notches #e1
 #e in the plate f f bearing against    
their sides2 but when pressed down to   
the proper level1 or till the notch #b  
came opposite f f1 they were not held   
fast1 but were relieved4 ,this furnished
 the depredator with the means of       
ascertaining which slides were pressed  
low enough1 or to the point for         
unlocking4 ,the notches #c1 #c in the   
slides are sometimes cut above the true 
notch #b1 sometimes below1 and at other 
times one on each side 7one above and   
one below72 they are not of sufficient  
depth to allow the cylinder to turn     
round1 but are intended to mislead any  
one who attempts to pick1 by his not    

knowing whether it is the true notch or 
otherwise1 or even whether the slider be
 higher or lower than the true notch4   
,we have not yet sufficiently described 
the key of the ,bramah lock4 ,one merit 
of the lock is the remarkable smallness 
of the key1 which renders it so         
conveniently portable4 ,the key1 as     
shewn in the upper part of the figure1  
has six notches or clefts at the end of 
its pipe or barrel2 these clefts are cut
 to different depths1 to accord with the
 proper extent of movement in the       
slides4 ,there is a small projection1   
#aj1 near the end of the pipe1 fitted to
 enter the notch ,d in the cylinder2    
this forces the cylinder round when the 
parts are all properly adjusted4 ,the   
bolt of the lock1 when properly shot or 
locked1 is prevented from being forced  
back by the stud c on the bottom1 ,f1 of
 the cylinder coming into a direct line 
with its centre of motion1 as shewn in  
fig4 #ci2 in this position no force1    
applied to drive the bolt back1 would   

have any tendency to turn the cylinder  
round4  ,illustration3 fig4 #ci4        
,section of the ,bramah cylinder4  ,to  
facilitate the comprehension of this    
very curious and beautiful mechanism1   
the cylinder is shewn in section in the 
annexed fig4 #ci1 the same letters and  
figures of reference being used as      
before4 ,in the whole of this           
description we have spoken of six       
slides1 and six only2 but ,bramah locks 
may be1 and have been1 constructed with 
a much larger number4  ,there have been 
several attempts made to modify the     
action of ,bramah's lock1 or to combine 
this action with that of some other     
inventor4 ,it will suffice to describe  
one of these4 ,the lock invented by ,mr4
 ,kemp of ,cork1 and for which a patent 
was obtained in #ahaf1 is called by him 
the ,union lock1 as combining the       
principles of ,barron's and ,bramah's   
locks4 ,it contains two1 three1 or more 
sliders or tumblers1 operated upon by   
two1 three1 or more concentric tubes4   

,these concentric tubes are of different
 lengths1 and are placed inside the     
barrel of the key2 so that the barrel   
may1 in fact1 be conceived to consist of
 a series of concentric tubes4 ,these   
tubes are made of such respective       
lengths as to push back the tumblers1   
sliders1 or pins which detain the bolt2 
and this to the precise extent that will
 bring certain notches in all the       
sliders to the position which will allow
 the bolt to pass4 ,the inventor gives  
this lock its distinctive appellation   
because it combines something of the    
pushing motion which ,bramah gives to   
his key1 with something of the          
tumbler-motion observable in ,barron's  
locks4 ,the principle of safety is      
considered here to rest chiefly on the  
extreme difficulty of imitating the key4
  ,mr4 ,bramah calculates the number of 
changes of position which the slides of 
his lock are capable of assuming before 
the right one would be attained4 8,let  
us suppose the number of levers1 slides1

 or other movables by which the lock is 
kept shut1 to consist of twelve1 all of 
which must receive a different and      
distinct change in their position or    
situation by the application of the key1
 and each of them likewise capable of   
receiving more or less than its due1    
either of which would be sufficient to  
prevent the intended effect4 ,it        
remains1 therefore1 to estimate the     
number producible1 which maybe thus     
attempted4 ,let the denomination of     
these slides be represented by twelve   
arithmetical progressionals2 we find    
that the ultimate number of changes that
 may be made in their place or situation
 is #dgi1jja1fjj2 and by adding one more
 to that number of slides1 they would   
then be capable of receiving a number of
 changes equal to #f1bbg1jbj1hjj2 and so
 on progressively1 by the addition of   
others in like manner to infinity4 ,from
 this it appears that one lock1         
consisting of thirteen of the           
above-mentioned sliders1 may 7by        

changing their places only1 without any 
difference in motion or size17 be made  
to require the said immense number of   
keys1 by which the lock could only be   
opened under all its variations40       
,,chapter ,,vii4  ,,american ,,locks4   
,the lock-manufacture in ,america has   
undergone some such changes as in       
,england4 ,the insufficiency of wards to
 the attainment of security has been for
 many years known2 and the unfitness of 
even tumblers to attain this end1       
without auxiliary contrivances1 has been
 fully recognised for a dozen years     
back4 ,in this1 and in other mechanical 
arts1 the ,american machinists depended 
primarily on the invention of the       
artisans in the mother country1 rather  
than on those of any continental        
,european state4 ,but the development of
 the art in the ,united ,states has not 
been wanting in originality2 the        
varieties of locks have been very       
numerous1 and many of them exceedingly  
ingenious4 ,it is not necessary1        

however1 to describe or depict any of   
those of simple form4 ,the warded locks 
of different countries very much        
resemble each other2 the intricate      
warded locks made in ,france in the last
 century have long fallen into disuse1  
in consequence of the general conviction
 that no arrangement of wards1 however  
intricate1 can afford the degree of     
security required in a good lock4 ,it   
will be more to the purpose1 therefore1 
to proceed at once to a notice of those 
,american locks which1 during the last  
few years1 have acquired some celebrity2
 first1 however1 noticing one of older  
date4  ,stansbury's lock1 invented in   
the ,united ,states about forty years   
ago1 may be regarded as a modification  
of the ,egyptian lock4 ,it had a bolt1  
case1 and key-hole somewhat similar to  
those of modern locks2 but there were   
peculiarities of construction in other  
respects4 ,there was a revolving plate1 
pierced with a series of holes1 and     
having a bit or pin which moved the     

bolt4 ,on the lock-case were a series of
 springs1 each having a pin at one end2 
and the arrangement was such that1 when 
the bolt was locked or unlocked1 each   
pin would be pressed into some one of   
the holes4 ,like as in the ,egyptian    
lock 7figs4 #a to #d71 each pin had to  
be pushed out1 and all of them          
simultaneously1 to allow the plate to   
turn and move the bolt4 ,the key was    
made with a barrel and bit2 and on the  
front end of the bit was a series of    
pins corresponding in position with the 
holes in the plate4 ,the mode of locking
 or unlocking was as follows3 the key   
was inserted in the key-hole1 and turned
 to a certain position2 it was then     
pressed in with some force1 until the   
pins on the key met those in the plate2 
when the latter1 yielding to the        
pressure1 left the plate free to turn   
and move the bolt4 ,modifications of the
 ,egyptian lock1 more or less resembling
 this1 have been brought out in some    
variety on both sides of the ,atlantic2 

but scarcely any have equalled in       
simplicity the curious wooden relic of  
by-gone ingenuity in the art of         
lock-making4  ,a lock made a few years  
ago by ,mr4 ,yale1 in the ,united       
,states1 somewhat resembles the ,bramah 
lock in having a cylinder or barrel1 or 
rather two concentric cylinders1 one    
working within the other4 ,these        
cylinders are held together by pins     
which pass through them both into the   
key-hole4 ,on the back of the inner     
cylinder is a pin that fits into a slot 
in the bolt1 and moves it whenever the  
cylinder is turned4 ,the pins that hold 
the cylinders together are each cut in  
two2 the pieces of the various pins     
differing in lengths as irregularly as  
possible4 ,the key is so peculiarly     
formed1 that1 on inserting it in the    
key-hole1 it thrusts the pins radially  
outwards2 each pin being pushed just so 
far that the joint of the pin shall     
coincide with the joint between the two 
cylinders4 ,the inner cylinder can then 

be turned1 by which the bolt is locked  
or unlocked4 ,if1 by the use of a false 
key1 any pin be pushed in too far1 it   
will be as ineffectual in opening the   
lock as if it were not thrust in far    
enough2 and some of these locks having  
been made with as many as forty pins1   
the chances are very numerous against   
the right combination being hit upon4   
,there is a combination of something    
like the ,egyptian with something like  
the ,bramah lock1 here attempted4  ,one 
of the principal constructions adopted  
in ,america a few years back for        
bank-locks is that of ,dr4 ,andrews of  
,perth ,amboy1 in ,new ,jersey4 ,it was 
up to that time 7#ahda7 believed that   
the best locks1 both of ,england and    
,america1 were proof against any        
attempts at picking derived from        
knowledge obtained by inspection through
 the key-hole2 but there still remained 
the danger that the sight of the true   
key1 or the possession thereof1 for only
 a few minutes1 would enable a dishonest

 person to produce a duplicate4 ,it was 
to contend against this difficulty that 
,dr4 ,andrews directed his attention2   
and he sought to obtain the desired     
object by constructing a lock1 the      
interior mechanism of which could be    
changed at pleasure4 ,the lock of his   
invention is furnished with a series of 
tumblers and a detector4 ,the tumblers  
are susceptible of being arranged in any
 desired order2 and the key has movable 
bits which can be arranged so as to     
correspond with the tumblers4 ,when the 
lock is fixed in its place1 no change   
can be made in the tumblers1 and        
consequently only one arrangement of the
 bits of the key will suit for the      
shooting and withdrawing of the bolt4   
,the owner can1 however1 before the     
fixing of the bolt1 adopt any           
arrangement of tumblers and bits which  
he may choose4 ,but though the tumblers 
cannot be actually re-arranged in any   
new order within the lock while the     
latter is fixed1 yet by an ingenious    

contrivance the tumblers can be so acted
 upon as to render the lock practically 
different from its former self4 ,the    
purchaser receives with his lock a      
series of small steel rings1 each ring  
corresponds in thickness with the       
thickness of some one of the bits of the
 key2 so that1 by suitable adjustment1  
any one of the bits may be removed from 
the key1 and a ring be substituted in   
its place4 ,the effect of this          
substitution is1 that the particular    
tumbler which corresponds with the ring 
is not raised by it2 it is drawn out    
with the bolt1 as if it were part of the
 bolt itself4 ,supposing the lock to be 
locked by this means1 the original key  
would not now unlock it2 for one of the 
tumblers has now been displaced1 and can
 only be re-adjusted by the same ring   
which displaced it4 ,if an attempt be   
made to open the lock by the original   
key1 or by the key in its original      
adjustment1 a detector is set in action1
 which indicates that a false key or    

other instrument has been put into the  
lock4 ,one1 or more than one1 of the    
bits may be removed from the key1 and   
rings be substituted1 and consequently  
one or more of the tumblers may be      
disturbed in this peculiar way2 so that 
the lock may change its character in all
 those permutating varieties which are  
so observable in most 8safety-locks40   
,the shape of the tumblers is1 of       
course1 such as to facilitate this      
action2 they have each an elongated     
slot1 and also two notches2 when a      
tumbler is raised by one of the bits of 
the key1 one of the notches closes      
around a stump fitted into the case of  
the lock1 and prevents the tumbler from 
being moved onward with the bolt2 but   
when a ring has been substituted for a  
bit on the key1 the tumbler cannot be   
raised at all2 it is carried onward by a
 stump on the bolt4  ,dr4 ,andrews is   
also the inventor of a lock which he    
terms the snail-wheel lock4 ,in this    
lock a series of revolving discs1 or    

wheels1 taking the place of the         
tumblers1 are mounted on a central pin1 
on which the pipe of the key is         
inserted4 ,each disc has a piece cut out
 of it1 into which the bit of the key   
enters1 and in turning round moves the  
discs according to the various lengths  
of the steps on the key4 ,on the outer  
edge of each disc is a notch1 and by the
 turning of the key all these notches   
are brought into a line1 so that a      
moveable tongue1 or toggle1 attached to 
the bolt1 falls into the notches2 the   
key is then turned the reverse way1 by  
which means the bolt is projected4      
,about the time when ,dr4 ,andrews      
invented his first lock1 ,mr4 ,newell1  
of the firm of ,day and ,newell of ,new 
,york1 constructed a lock which         
possessed the same distinctive          
peculiarity as that of ,andrews1 viz4   
that the key might be altered any number
 of times without rendering it necessary
 to remove the lock or change its       
internal mechanism4 ,this was brought   

about1 however1 in a different manner4  
,instead of having1 as in the ,andrews  
lock1 a two-fold movement to every      
tumbler1 ,mr4 ,newell employed two sets 
of tumblers1 the one set to receive     
motion from the other1 and having       
different offices to fill1 to be acted  
upon by the key in respect to the first 
series1 and to act upon the bolt in     
respect to the second4 ,calling these   
two sets primary and secondary1 the     
action of the lock may be briefly       
described as follows4 ,a primary tumbler
 being raised to the proper height by   
the proper bit in the key1 raises the   
corresponding secondary tumbler2 the    
secondary tumbler is held up in a given 
position during the locking1 while the  
primary becomes pressed by a spring into
 its original position4 ,it results from
 this arrangement that the bolt cannot  
be unlocked until the primary tumbler   
has been raised to the same height as   
before1 so as to receive the tongue of  
the secondary tumbler4 ,and as this is  

the case in respect to any one primary  
and its accompanying secondary tumblers1
 so is it the case whether each set     
comprises four1 five1 or any other      
number4 ,the key may be altered at      
pleasure1 and will in any form equally  
well shoot the bolt2 but the lock can   
only be unfastened by that arrangement  
of key which fastened it4  ,it is1      
however1 desirable to trace the course  
of improvements more in detail1 because 
every successive change illustrates one 
or other of the several properties      
required in a good lock4 ,messrs4 ,day  
and ,newell's lock was not finally      
brought to an efficient form without    
many attempts more or less abortive4    
,mr4 ,newell conceived the idea of      
applying a second series of tumblers1 so
 placed as to be acted on by the first  
series4 ,each of these secondary        
tumblers had an elongated slot1 such    
that a screw could pass through all of  
them2 the screw having a clamp to       
overlap the tumblers on the inside of   

the lock4 ,the head of the screw rested 
in a small round hole on the back of the
 lock1 so placed as to form a secondary 
key-hole1 to which a small key was      
fitted4 ,there was thus a double system 
of locking1 effected in the following   
way3 when the large key had been        
applied1 and had begun to act on the    
primary tumblers1 the small key was used
 to operate on the clamp-screw1 and thus
 bind all of the secondary tumblers     
together1 ensuring their position at the
 exact heights or distances to which the
 primary key had caused them to be      
lifted4 ,the bolt was then free to be   
shot1 and the first series of tumblers  
reverted to their original position4    
,but such an arrangement has obvious    
inconveniences4 ,few persons would incur
 the trouble of using two keys2 and     
besides this1 there were not wanting    
certain defects in the action and       
reaction of the several parts2 for if   
the clamp-screw were to be left         
unreleased1 the first series of tumblers

 would be upheld by the second series in
 such a way that the exact impression of
 the lengths of the several bits of the 
key could be obtained through the       
key-hole while the lock was unlocked or 
the bolt unshot4 ,to remedy one or both 
of these evils was the next object of   
,mr4 ,newell's attention4 ,he made a    
series of notches or teeth in each of   
the secondary tumblers1 corresponding in
 mutual distance with the steps or bits 
of the key2 and opposite these notched  
edges he placed a dog or lever1 with a  
projecting tooth suitable to fall into  
the notches when adjusted properly in   
relation to each other4 ,when the key   
was used1 the primary tumblers were     
raised in the usual way1 and acted on   
the secondary tumblers2 these latter    
were so thrown that the dog-tooth caught
 in the notches and held them fast1     
thereby rendering the same service as   
the clamp-screw and the small key in the
 former arrangement4 ,no other relative 
position of the bits of the key could   

now unlock the lock4  ,still1           
improvement as it was1 this change was  
not enough2 ,mr4 ,newell found that his 
lock1 like all the locks that had       
preceded it1 was capable of being picked
 by a clever practitioner2 and candidly 
admitting the fact1 he sought to obtain 
some new means of security4 ,he tried   
what a series of complicated wards would
 do1 in aid of the former mechanism2 but
 the result proved unsatisfactory4 ,his 
next principle was to provide a number  
of false notches on the abutting parts  
of the primary and secondary tumblers1  
with alterations in other parts of the  
apparatus4 ,the theory now depended upon
 was this1 that if the bolt were        
subjected to pressure1 the tumblers     
would be held fast by false notches1 and
 could not be raised by any lock-picking
 instrument4 ,to increase the security1 
a steel-curtain was so adjusted as to   
cover1 or at least protect1 the         
key-hole4 ,great anticipations were     
entertained of this lock1 but they were 

destined to be negatived4 ,a clever     
,american machinist1 ,mr4 ,pettit1      
accepted ,messrs4 ,day and ,newell's    
challenge 7#ejj dollars to any one who  
could pick this lock72 he succeeded in  
picking the lock1 and thus won the      
prize4  ,once again disappointed1 ,mr4  
,newell re-examined the whole affair1   
and sought for some new principle of    
security that had not before occurred to
 him4 ,he had found that1 modify his    
lock how he might1 the sharp-eyed and   
neat-fingered mechanician could still   
explore the interior of the lock in such
 a way as to find out the relative      
positions of the tumblers1 and thus     
adapt their means to the desired end4   
,how1 therefore1 to shut out this       
exploration altogether became the       
problem2 how to make a lock1 the works  
of which should be parautoptic--to coin 
a word from the ,greek1 which should    
signify concealed from view4 ,the result
 of his labours was the production of   
the ,american bank-lock now known by    

that name4 ,the details of this lock may
 now conveniently be given4             
,illustration3 fig4 #dj4 ,the ,american 
,parautoptic lock2 bolt unshot4         
,illustration3 fig4 #da4 ,the same with 
the bolt shot4  ,in fig4 #dj the lock is
 represented in its unlocked state1 with
 the cover or top-plate removed2 the    
auxiliary tumbler and the detector-plate
 are also removed4 ,in fig4 #da it is   
represented as locked1 with the cover   
and the detector-plate also removed1 and
 the auxiliary tumbler in its place4 ,in
 these two figures1 the same letters of 
reference apply to the same parts1      
unless otherwise stated4 ,b ,b is the   
bolt2 ,t are the first series of movable
 slides or tumblers2 s shews the        
tumbler-springs2 ,t the secondary series
 of tumblers2 and ,t the third or       
intermediate series--these latter coming
 between the first and secondary series2
 ,p ,p are the separating plates between
 the several members of the first series
 of tumblers2 s are the springs for     

lifting the intermediate tumblers4 ,on  
each of the secondary tumblers ,t is a  
series of notches1 corresponding in     
mutual distance with the difference in  
the lengths of the movable bits of the  
key4 ,it thence happens that1 when the  
key is turned in the lock to lock it1   
each bit raises its proper tumbler1 so  
that some one of these notches shall    
present itself in front of the tooth t  
in the dog or lever ,l ,l4 ,when the    
bolt ,b is projected by the action of   
the key1 it carries with it the         
secondary tumblers ,t1 and presses the  
tooth t into the notches2 in so doing1  
it withdraws the tongues d from between 
the jaws j j of the intermediate        
tumblers ,t1 and allows the first and   
intermediate tumblers to fall to their  
original position4 ,by the same         
movement1 the secondary tumblers ,t     
become held in the position given to    
them by the key1 by means of the tooth t
 being pressed into the several notches1
 as shewn in the closed state of the    

lock 7fig4 #da74 ,now let us see what   
results if any attempt be made to open  
the lock with any arrangement of key but
 that by which it has been locked4 ,in  
such case1 the tongues d will abut      
against the jaws j j1 preventing the    
bolt from being withdrawn2 and should an
 attempt be made to ascertain which     
tumbler binds and requires to be moved1 
the intermediate tumbler ,t 7which      
receives the pressure71 being behind the
 iron wall ,i ,i1 which is fixed        
completely across the lock1 prevents the
 possibility of its being reached       
through the key-hole2 and the first     
tumblers ,t are quite detached at the   
time1 thereby making it impossible to   
ascertain the position of the parts in  
the inner chamber behind the wall ,i ,i4
 ,k is the drill-pin1 on which the key  
fits2 and ,c is a revolving ring or     
curtain1 which turns round with the key1
 and prevents the possibility of        
inspecting the interior of the lock     
through the key-hole4 ,should1 however1 

this ring be turned to bring the opening
 upwards1 a detector-plate ,d1 fig4 #db1
 is immediately carried over the        
key-hole by the motion of a pin p upon  
the auxiliary tumbler ,t1 which is      
lifted by the revolution of the ring ,c1
 thereby effectually closing the        
key-hole4 ,as an additional protection1 
the bolt is held from being unlocked by 
the stud or stump ,s bearing against the
 detector-plate2 and1 moreover1 the     
lever l l holds the bolt1 when locked1  
until it is released by the tail of the 
detector-plate pressing the pin p2 l is 
a lever which holds the bolt on the     
upper side1 when locked1 until it is    
lifted by the tumblers acting on the pin
 p2 ,x are separating-plates between the
 intermediate tumblers ,t2 u u are the  
studs for preserving the parallel motion
 of the different tumblers4             
,illustration3 fig4 #db4 ,the detector  
plate of the ,parautoptic lock4  ,fig4  
#dc represents the key in two different 
forms1 or with the bits differently     

arranged4 ,either form will lock the    
lock1 but the other will not then unlock
 it4 ,the end of the key is represented 
in fig4 #dd1 shewing the screw which    
fixes the bits in their places4 ,the    
bits for a six-bitted key are shewn     
separately in fig4 #de4  ,illustration3 
fig4 #dc4 ,key of the ,parautoptic lock4
  ,illustration3 fig4 #dd4 ,end view of 
the key4  ,illustration3 fig4 #de4      
,separate bits of the key4  ,in #ahdg   
the parautoptic lock was exhibited at   
,vienna before the ,national ,mechanics'
 ,institute of ,lower ,austria2 and     
towards the close of the year ,mr4      
,belmont1 consul-general of ,austria at 
,new ,york1 placed in the hands of      
,messrs4 ,day and ,newell a letter1 a   
diploma1 and a gold medal1 forwarded by 
the ,institute4 ,the letter was from the
 president of the ,institute to ,mr4    
,newell1 and was couched in the         
following terms3  8,the ,institute of   
,lower ,austria1 at its last monthly    
session1 has passed the unanimous       

resolution to award to you its gold     
medal1 as an acknowledgment of the      
uncommon superiority of the             
combination-lock of your invention2 and 
this resolution was ratified in its     
general convention held on the #ajth    
instant4  8,whilst ,i1 as president of  
this ,institute1 rejoice in seeing the  
services which by this invention you    
have rendered to the locksmith's art    
thus appreciated and recognised1 ,i     
transmit to you1 enclosed1 the said     
medal1 together with the documents      
relating to it2 at the same time        
availing myself of this opportunity to  
assure you of my esteem4    8,,colloredo
 ,,mannsfeld4    8,vienna1 ,may #cast1  
#ahdg40  ,the diploma and the medal were
 similar to other honorary distinctions 
of the same class1 and need not be      
described here2 but the report of the   
special committee may be given1 as it   
expresses the opinions of the ,viennese 
machinists on the relative principles by
 which safety is sought to be obtained  

in different kinds of locks4  ,,report  
,of a ,special ,committee on the new    
,parautoptic ,permutation ,lock of the  
,american ,newell1 made known to the    
,lower ,austrian ,institute by the      
,councillor1 ,professor ,reuter1 and on 
the motions relating to it made   by the
 same and accepted by the ,institute4   
,presented at the monthly   meeting1    
,april #fth1 #ahdg1 by ,mr4 ,paul       
,sprenger1 ,aulic ,councillor on        
,public ,works1 c4 c4                   
,,gentlemen3--,at our last monthly      
meeting1 ,mr4 ,reuter1 ,aulic           
,councillor   and ,secretary of the     
,institute1 directed your attention to a
 newly   invented lock of ,mr4 ,newell1 
of ,north ,america1 which was           
represented   as excelling all other    
changeable combination-locks hitherto   
known1   and as being without a rival4  
,the ,special ,committee which was      
intrusted with the examination of this  
lock1 and of the motions made by the    
said ,secretary1 and accepted by   the  

,institute1 has conferred on me the     
honour of making you acquainted   with  
the results of its investigations4      
,the attention of your committee was    
chiefly occupied with the three         
questions proposed by the said ,aulic   
,councillor in relation to the   lock in
 question3    ,first3 ,whether the idea 
of ,mr4 ,newell was of any practical    
value for   already existing and        
still-to-be-invented combination-locks2 
,secondly3 ,whether the idea was of     
sufficient importance to be   published 
and minutely described in the           
transactions of the said   ,institute2  
and    ,thirdly3 ,whether the merits of 
the inventor were of sufficient         
importance to entitle him to a          
distinction from the said ,institute4   
,the deliberations on the first         
question1 viz4 the newness of the idea1 
and of its practical value1 would of    
necessity enlist the particular         
attention of your committee1 especially 
since by far the greater   number of its

 members are by their avocation called  
upon to be   interested in the execution
 of all kinds of locks4    ,it is       
therefore the unanimous opinion of your 
committee1 that the   idea of the       
,american ,parautoptic                  
,combination-,lock is entirely new and  
without example4    ,the                
combination-locks with keys have1 with  
few exceptions1 such an   arrangement   
that a determinate number of movable    
parts 7the so-called                    
combination-parts7 must by the turning  
of the key be raised or lifted   into a 
certain position1 if it is desired to   
project the bolt1 or1   what is the same
 thing1 to lock it out2 consequently    
these parts1 or1   as they are          
technically termed1 tumblers1 could not 
be transposed or   changed1 from the    
circumstance that the key-bit was one   
solid piece1   with various steps or    
notches adapted to the several tumblers1
 and one   impression from it destroyed 
the security of the lock4    ,in order1 

however1 to add more security to such a 
combination-lock1   and to make the key1
 in case it should be lost1 or any      
counterfeit   made from a wax           
impression1 useless for an unlawful     
opening of the   lock1 another step was 
taken3 the key-bit was made to consist  
of   several bits or movable parts1 in  
such a manner that the owner of the     
lock was enabled to change the bits1 and
 to form1 as it were1 new   keys        
different from the former4 ,but since   
the bolt of the lock can   only be      
projected whilst the combination parts  
or tumblers are in a   certain position1
 which position depends upon the order  
of the bits in   the key1 it is evident 
that the owner1 when changing the key1  
must at   the same time make a          
corresponding change in the position of 
the   tumblers in the lock itself1      
before the lock can be of any use for   
the   newly changed shape of the key1   
which rendered it troublesome1 and      
impracticable for the purpose designed1 

from the fact that no positive   change 
could be made in the lock1 without      
taking it from the door1 and   then     
taking the tumblers out of the case1 to 
change them in a suitable   form for the
 key4    ,this principle of changing the
 lock is rarely adhered to1 as few men  
understand the machinery of a lock      
sufficiently to undertake the task2     
and this circumstance rendered the lock 
quite as insecure as the   former one   
described4    ,another step toward the  
perfection of combination-locks         
consisted in   this1 that the key       
remains unaltered whilst the combination
 parts of   the lock can1 before it is  
locked1 be brought into different       
positions   by means of movable plates  
on the frame of the lock4 ,these plates 
were   arranged by hand to certain      
figures1 and depended on the memory for 
adjustment at each time the bolt was to 
be locked out or in1 the key   operating
 only on the bolt1 to move it back and  
forth when the plates   were set in     

proper positions for the purpose2 and   
should the owner   forget the           
arrangement of the plates1 after        
projecting the bolt1 his   key is of no 
use to him1 and he must resort to the   
skill of the   locksmith to gain access4
    ,the same case may occur in the far 
less perfect ring-lock of ,reynier1     
which is operated without keys1 and is  
opened by means of the rings   being    
turned in a particular position2 on     
these rings are usually   stamped       
letters1 which1 by introducing some word
 readily suggested to   the memory1 thus
 point out the relative position of the 
rings4    ,but although in case of these
 ring-locks the owner is enabled to     
produce a change in the rings in such a 
manner that the opening of   the lock   
can1 as it were1 only become possible by
 rightly arranging   the altered        
position of the letters1 still this lock
 of ,reynier's does   not possess that  
safety and perfection which could have  
insured it   universal application4     

,m4 ,crivelli1 formerly professor at    
,milan1 has given a minute   description
 of the imperfection of ring-locks      
generally1 in the annals   of the       
,imperial ,royal ,polytechnic           
,institute4    ,it is the unanimous     
conviction of your committee that the   
,american   ,lock of ,newell surpasses1 
in the ingenuity displayed in its       
construction1 all other locks heretofore
 known1 and more especially in   this1  
that the owner can1 with the greatest   
facility1 change at   pleasure the      
interior arrangement of his lock to a   
new and more   complex one1 at every    
moment of his life1 simply by altering  
the   arrangement of the bits in the    
key1 and this is accomplished without   
removing the lock or any part of it from
 its position on the door4    ,its      
operation is as follows3--,at the       
closing or locking of the lock1   whilst
 the bolt is projecting1 the movable    
combination parts assume   precisely the
 position prescribed to them by the key1

 according to the   particular          
arrangement of its bits at the time the 
key is turned4    ,the combination parts
 do not consist in one set of tumblers  
only1 such   as are found in all other  
locks1 but there are three distinct sets
 or   component parts fitting into each 
other4 ,when the bolt is projected1   it
 dissolves the mutual connexion of the  
constituent pieces1 and   carries along 
with it such as are designedly attached 
to it1 and which   assume the particular
 positions given them by the key in its 
revolution4 ,these parts are rendered   
permanent in their given form by   means
 of a lever adapted for the purpose1    
while the parts not united   with the   
bolt are pressed down by their springs  
to their original   places4    ,if now  
the bolt is to be returned again1 i4 e4 
if the lock is to be   unlocked1 then   
the constituent pieces or tumblers which
 are in the   original state must1 by   
means of the key1 be again raised into  
that   position in which they were when 

the lock was closed1 as otherwise the   
constituent parts attached to the bolt  
would not lock in with the   former1 and
 the bolt could not be returned4        
,nothing1 therefore1 but   the precise  
key which had locked the lock can effect
 the object4    ,this idea in itself1   
considered by your committee1 is as     
ingenious as   it is new1 and is        
accompanied by a perfection in its      
execution which   reflects the highest  
honour on ,mr4 ,newell1 the inventor and
   manufacturer of the lock4    ,the    
lock is built strong and solid1 and the 
several parts are   admirably adapted to
 the functions which they are designed  
to perform4   ,the walls of steel or    
iron which separate the security parts  
from the   tumblers1 and the cylinder   
which revolves with the key1 present    
formidable barriers to all descriptions 
of pick-locks1 and render the   lock a  
most positive and reliable security4    
,the tumblers consist of   rolled very  
smooth steel plates1 in which the       

fire-crust has not been   filed away1   
partly in order that the lock might not 
need oiling1 as   all these parts are   
very smooth1 and partly that the        
combination   pieces might not easily   
rust1 a thing to which the adhering     
fire-crust   is not favourable4 ,the    
springs1 which by the turning of the key
 must   be raised together with the     
tumblers1 are attached to levers1 and   
press upon the latter at their centre of
 gravity1 in consequence of   which all 
crowding towards either side is         
prevented1 and the key can   be turned  
with facility1 in spite of the many     
combination parts which   it has to     
raise2 and the springs themselves are by
 their positions so   little called into
 action1 that their strength can never  
be impaired   by use4    ,the lock has  
also another very complete arrangement  
in the   detector-tumbler1 which is     
attached to the cap or covering of the  
lock4 ,this tumbler1 on turning the key 
either way1 closes the   key-hole1 and  

not only prevents the use of false      
instruments in the   lock1 but detects  
all attempts at mutilating its interior 
parts4    ,this lock is especially      
useful for locking bank-vaults1         
magazines1   counting-houses1 and       
iron-safes1 in which valuable effects1  
money1 or   goods are to be deposited   
for safe keeping4 ,when it is considered
 that   the bits of the key belonging to
 this lock can be transferred into      
every possible form within its limits1  
and since the construction of   the lock
 admits of every combination of the     
slides resulting from the   changes of  
the key1 therefore the lock in question 
is1 in every   respect1 deserving of the
 appellation given to it by the         
,secretary of   the ,institute1 namely1 
the ,universal ,combination ,lock2 and  
justly so1   when we consider that the  
ten bits attached to the key admit of   
three   millions of permutations1 and   
upward2 consequently forming that number
   of different kinds of keys and locks4

    ,if we consider further1 that we    
need not be limited to the given bit1   
but that others can be applied1         
differing in their dimensions from the  
former2 and again1 if we consider that  
from every system arising from   a      
difference in their relative dimensions1
 a large number of new keys   differing 
from each other will result1 and that   
this can be effected   in a space       
scarcely occupying a square inch1--then 
we cannot refrain   from confessing that
 the human mind1 within this small      
space1 has   shewn itself to be         
infinitely great4    ,after this        
preliminary and general exposition1 your
 committee can   answer the three       
questions propounded to them the more   
briefly1 as the   locks heretofore known
 have all been noticed4    ,to question 
first4--,on the practical value of the  
invention of ,mr4   ,newell1 your       
committee were unanimous and positive   
that the principle   on which it is     
based should be preserved4    ,to       

question second4--,for this reason the  
committee deemed it desirable   that a  
drawing and description of the ,american
 lock in question should   be published 
in the ,transactions of the ,institute  
of ,lower ,austria4    ,to question     
third4--,with regard to the claims of   
the inventor1 ,mr4   ,newell1 to an     
honorary distinction from the ,institute
 of ,lower   ,austria1 the committee    
recommend that he be presented with a   
,diploma   of honourable mention and a  
,gold ,medal4    ,the members of your   
committee1 consisting mostly of         
fellow-tradesmen   of ,mr4 ,newell1     
experience great satisfaction in the    
fact that it has   fallen to their lot  
to vote to their colleague on the other 
side of   the ocean an acknowledgment of
 his successful ingenuity1 and they     
close the ,report with the request that 
the ,institute will transmit to   ,mr4  
,newell of ,new ,york1 in ,north        
,america1 the ,diploma and ,gold ,medal1
   together with a copy of this ,report1

 according to the motion of the   ,aulic
 ,councillor and ,professor ,reuter4    
,an exact copy of the original ,report  
as preserved in the archives of   the   
,national ,mechanics' ,institute of     
,lower ,austria4    ,,dr4 ,,schwartz1   
,assistant ,secretary of the ,institute4
  ,there are other circumstances        
connected with the ,american bank-lock1 
in relation to events both in the       
,united ,states and in ,england1 to     
which attention will be directed in a   
subsequent chapter4  ,the ,english      
patent for ,messrs4 ,day and ,newell's  
lock1 dated ,april #ae1 #ahea1 runs as  
follows3 8,the object of the present    
improvements is the constructing of     
locks in such manner that the interior  
arrangements1 or the combination of the 
internal movable parts1 may be changed  
at pleasure according to the form given 
to1 or change made in1 the key1 without 
the necessity of arranging the movable  
parts of the lock by hand1 or removing  
the lock or any part thereof from the   

door4 ,in locks constructed on this plan
 the key may be altered at pleasure2 and
 the act of locking1 or throwing out the
 bolt of the lock1 produces the         
particular arrangement of the internal  
parts which corresponds to that of the  
key for the time being4 ,while the same 
is locked1 this form is retained until  
the lock is unlocked or the bolt        
withdrawn1 upon which the internal      
movable parts return to their original  
position with reference to each other2  
but these parts cannot be made to assume
 or be brought back to their original   
position1 except by a key of the precise
 form and dimensions as the key by which
 they were made to assume such          
arrangement in the act of locking4 ,the 
key is changeable at pleasure1 and the  
lock receives a special form in the act 
of locking according to the key         
employed1 and retains that form until in
 the act of unlocking by the same key it
 resumes its original or unlocked state4
 ,the lock is again changeable at       

pleasure1 simply by altering the        
arrangement of the movable bits of the  
key2 and the key may be changed to any  
one of the forms within the number of   
permutations of which the parts are     
susceptible40  ,the 8claims0 put forth  
under this patent are the following3--  
8#a4 ,the constructing1 by means of a   
first and secondary series of slides or 
tumblers1 of a changeable lock1 in which
 the particular form or arrangement of  
parts of the lock1 imparted by the key  
to the first and secondary series of    
slides or tumblers1 is retained by a    
cramp-plate4  8#b4 ,the constructing1 by
 means of a first and secondary series  
of slides or tumblers1 of a changeable  
lock1 in which the peculiar form or     
arrangement of parts of the lock1       
imparted by the key1 is retained by     
means of a tooth or teeth1 and notches  
on the secondary series of slides or    
tumblers4  8#c4 ,the application to     
locks of a third or intermediate series 
of slides or tumblers4  8#d4 ,the       

application of a dog with a pin         
over-lapping the slide or tumblers1 for 
the purpose of holding-in the bolt when 
the lock is locked or unlocked4  8#e4   
,the application of a dog operated on by
 the cap or detector-tumbler for holding
 the bolt4  8#f4 ,the application of a  
dog for the purpose of holding the      
internal slide or tumbler4  8#g4 ,the   
application to locks of curtains or     
rings1 turning and working eccentrically
 to the motion of the key1 for          
preventing access to the internal parts 
of the lock4  8#h4 ,the application to  
locks of a safety-plug or               
yielding-plate1 at the back of the      
chamber formed by such eccentric        
revolving curtain or ring4  8#i4 ,the   
application to locks of a strong        
metallic wall or plate1 for the purpose 
of separating the safety and other parts
 of the lock from each other1 and       
preventing access to such parts by means
 of the key-hole4  8#aj4 ,the           
application to locks of a cap or        

detective tumbler1 for the purpose of   
closing the key-hole as the key is      
turned4  8#aa4 ,the constructing a key  
by a combination of bits or movable     
pieces1 with tongues fitted into a      
groove and held by a screw4  8#ab4 ,the 
constructing a key having a groove in   
its shank to receive the detector       
tumbler40  ,illustration3 fig4 #df4     
,movable stump4  ,when the ,american    
locks became known in ,england1 ,mr4    
,hobbs undertook the superintendence of 
their manufacture1 and their            
introduction into the commercial world4 
,such a lock as that just described must
 necessarily be a complex piece of      
mechanism2 it is intended for use in the
 doors of receptacles containing        
property of great value2 and the aim has
 been to baffle all the methods at      
present known of picking locks1 by a    
combination of mechanism necessarily    
elaborate4 ,such a lock must of         
necessity be costly2 but in order to    
supply the demand for a small lock at   

moderate price1 ,mr4 ,hobbs has         
introduced what he calls a protector    
lock4 ,this is a modification of the    
ordinary six-tumbler lock4 ,it bears an 
affinity to the lock of ,messrs4 ,day   
and ,newell1 inasmuch as it is an       
attempt to introduce the same principle 
of security against picking1 while      
avoiding the complexity of the          
changeable lock4 ,the distinction which 
,mr4 ,hobbs has made between secure and 
insecure locks will be understood from  
the following proposition1 viz4 8that   
whenever the parts of a lock which come 
in contact with the key are so affected 
by any pressure applied to the bolt1 or 
to that portion of the lock by which the
 bolt is withdrawn1 as to indicate the  
points of resistance to the withdrawal  
of the bolt1 such a lock can be picked40
 ,fig4 #dg exhibits the internal        
mechanism of this new patent lock4 ,it  
contains the usual contrivances of      
tumblers and springs1 with a key cut    
into steps to suit the different heights

 to which the tumblers must be raised4  
,the key is shewn separately in fig4    
#dh4 ,but there is a small additional   
piece of mechanism1 in which the tumbler
 stump shewn at s in figs4 #df and #dg  
is attached2 which piece is intended to 
work under or behind the bolt of the    
lock4 ,in fig4 #dg1 b is the bolt2 t t  
is the front or foremost of the range of
 six tumblers1 each of which has the    
usual slot and notches4 ,in other       
tumbler-locks the stump or stud which   
moves along these slots is riveted to   
the bolt1 in such manner that1 if any   
pressure be applied in an attempt to    
withdraw the bolt1 the stump becomes    
pressed against the edges of the        
tumblers1 and bites or binds against    
them4 ,how far their biting facilitates 
the picking of a lock will be shewn     
further on2 but it will suffice here to 
say1 that the movable action given to   
the stump in the ,hobbs lock transfers  
the pressure to another quarter4 ,the   
stump s is riveted to a                 

peculiarly-shaped piece of metal h h    
7fig4 #df71 the hole in the centre of   
which fits upon a centre or pin in a    
recess formed at the back of the bolt2  
the piece moves easily on its centre1   
but is prevented from so doing          
spontaneously by a small binding spring4
 ,the mode in which this small movable  
piece takes part in the action of the   
lock is as follows3 when the proper key 
is applied in the usual way1 the        
tumblers are all raised to the proper   
heights for allowing the stump to pass  
horizontally through the gating2 but    
should there be an attempt made1 either 
by a false key or by any other          
instrument1 to withdraw the bolt before 
the tumblers are properly raised1 the   
stump becomes an obstacle4 ,meeting with
 an obstruction to its passage1 the     
stump turns the piece to which it is    
attached on its centre1 and moves the   
arm of the piece p so that it shall come
 into contact with a stud riveted into  
the case of the lock2 and in this       

position there is a firm resistance     
against the withdrawal of the bolt4 ,the
 tumblers are at the same moment        
released from the pressure of the stump4
 ,there is a dog or lever d1 which      
catches into the top of the bolt1 and   
thereby serves as an additional security
 against its being forced back4 ,at k is
 the drill-pin on which the pipe of the 
key works2 and r is a metal piece on    
which the tumblers rest when the key is 
not operating upon them4  ,illustration3
 fig4 #dg4 ,hobbs's ,protector ,lock4   
,illustration3 fig4 #dh4 ,the key4      
,another lock1 patented by ,mr4 ,hobbs  
in #aheb1 has for its object the        
absolute closing of the key-hole during 
the process of locking4 ,the key does   
not work or turn on its own centre1 but 
occupies a small cell or chamber in a   
revolving cylinder1 which is turned by a
 fixed handle4 ,the bit of the movable  
key is entirely separable from the shaft
 or stem1 into which it is screwed1 and 
may be detached by turning round a small

 milled headed thumb-screw4 ,the key is 
placed in the key-hole in the usual way1
 but it cannot turn2 its circular       
movement round the stem as an axis is   
prevented by the internal mechanism of  
the lock2 it is left in the key-hole1   
and the stem is detached from it by     
unscrewing4 ,by turning the handle1 the 
key-bit1 which is left in the chamber of
 the cylinder1 is brought into contact  
with the works of the lock1 so as to    
shoot and withdraw the bolt4 ,this      
revolution may take place whether the   
bit of the movable key occupy its little
 cell in the plate or not2 only with    
this difference--that if the bit be not 
in the lock1 the plate revolves without 
acting upon any of the tumblers2 but if 
the bit be in its place1 it raises the  
tumblers in the proper way for shooting 
or withdrawing the bolt4 ,it will be    
understood that there is only one       
key-hole1 namely1 that through which the
 divisible key is inserted2 the other   
handle or fixed key working through a   

hole in the cover of the lock only just 
large enough to receive it1 and not     
being removable from the lock4 ,as soon 
as the plate turns round so far as to   
enable the key-bit to act upon the      
tumblers1 the key-hole becomes entirely 
closed by the plate itself1 so that the 
actual locking is effected at the very  
time when all access to the interior    
through the key-hole is cut off4 ,when  
the bolt has been shot1 the plate comes 
round to its original position1 it      
uncovers the key-hole1 and exhibits the 
key-bit occupying the little cell into  
which it had been dropped2 the stem is  
then to be screwed into the bit1 and the
 latter withdrawn4 ,it is one           
consequence of this arrangement1 that   
the key has to be screwed and unscrewed 
when used2 but through this arrangement 
the key-hole becomes a sealed book to   
one who has not the right key4 ,nothing 
can be moved1 provided the bit and stem 
of the key be both left in2 but by      
leaving in the lock the former without  

the latter1 the plate can rotate1 the   
tumblers can be lifted1 and the bolt can
 be shot4     ,,chapter ,,viii4  ,,the  
,,lock ,,controversy3 ,,previous ,,to   
,,the ,,date ,,of ,,the ,,great         
,,exhibition4   ,it must be evident1    
even on a cursory glance at the past    
history of the lock-manufacture1 that   
the prime motive for the introduction of
 novelties and improvements in          
construction is the desirability of     
producing a lock which no one can open  
without the proper key4 ,from the       
earliest and simplest lock1 down to the 
latest and most complex1 this object has
 been constantly held in view2 and every
 clear proof or evidence that this      
object has not been attained has led to 
the invention of some new contrivance4  
,it has been a succession of            
struggles--to attain security--to shew  
that this security has not been         
attained--to make a further and more    
ingenious attempt--to detect the weak   
point in this renewed attempt--and so   

on4 ,we need not repeat here1 what was  
stated in an early chapter1 that benefit
 must ultimately result from a candid   
discussion of this question4 ,when ,m4  
,raumur proposed to explain how the     
locks of his day could be picked or     
opened without the true key1 his object 
was to shew to persons who were not     
locksmiths how far they could depend    
upon the principle of security offered  
by locks4 ,but before proceeding on his 
inquiry1 the illustrious naturalist     
asks1 8,ne craindra-t-on pas que nous ne
 donnions en mme tems des leons aux     
voleurs80 ,and he replies1 8,il n'y a   
pas grande apparence qu'ils viennent les
 chercher ici1 et qu'ils en aient       
besoin2 ils sont plus grands matres que 
nous dans l'art d'ouvrir les portes4    
,apprenons donc l'art d'ouvrir les      
portes fermes1 afin d'apprendre celui de
 les fermer d'une manire qui ne laisse  
rien ou qui laisse peu  craindre40#e    
#e 8,but is there not this danger1 that 
at the same time we shall be   giving   

lessons to the thieves8 ,it is not very 
probable that they will   seek          
instruction of us1 or that they have any
 need of it2 they are   greater masters 
in the art of opening doors than we can 
pretend to be4   ,let us then learn the 
art of opening locked doors1 in order   
that we   may acquire that of securing  
them in such a way as to leave little or
   nothing to be feared on account of   
their security40  ,before treating of   
lock controversies and lock violability 
in ,england1 it will be desirable first 
to refer to ,america1 where this subject
 attracted much attention some years    
earlier than the ,great ,exhibition--an 
,exhibition which will always be        
associated in a remarkable manner with  
the history of locks4  ,soon after the  
inventions by ,dr4 ,andrews and ,mr4    
,newell1 in #ahda 7described in a former
 chapter71 the rivalry between the two  
locks ran high2 each lock being         
#8unpickable1' according to the estimate
 of its inventor4 ,mr4 ,newell thought  

the best mode of shewing the superiority
 of his own lock would be by picking    
that of his competitor2 and after       
several trials1 he succeeded in bringing
 into practical application that system 
of picking which we may designate the   
mechanical1 as contra-distinguished from
 the arithmetical4 ,mr4 ,newell not only
 picked ,dr4 ,andrews' lock1 but he     
wound up the enterprise by picking his  
own6 ,he was probably the first person  
who honestly confessed to having picked 
his own unpickable lock4 ,this discovery
 led ,mr4 ,newell1 as has been noticed  
in a former page1 to the invention of   
the triple-action or parautoptic lock4  
,the mechanical principle1 as applied to
 the picking of a tumbler lock1 is      
nearly the same whatever form of        
construction be made the medium of      
experiment4 ,when a pressure is applied 
to the bolt sufficient to unlock it if  
the tumbler-obstructions were removed1  
the edges of the tumbler bite or bind   
against the stump of the bolt1 so as not

 to move up and down with such facility 
as under ordinary circumstances4 ,by    
carefully trying with a small instrument
 each tumbler1 and moving it until the  
bite ceases1 the gating of that         
particular tumbler may be brought to the
 exact position for allowing the stump  
of the bolt to pass through it4 7,see   
page #aah47  ,this violability is       
observable in the tumbler-locks under   
very varied forms of construction4 ,mr4 
,newell1 after he had picked his own    
lock1 devised a series of complicated   
wards1 to add to the difficulty of      
reaching the tumblers2 but he could not 
thereby get rid of the importance of    
this fact1 that wherever a key can go1  
instruments of a suitable size and form 
could follow3 his wards did not render  
his lock inviolable4 ,his next          
contrivance was to notch the abutting   
parts of the primary and secondary      
tumblers1 or the face of the stump and  
the ends of the tumblers2 but this      
failed also4 ,mr4 ,h4 ,c4 ,jones1 of    

,newark1 ,n4 ,j41 added to all this a   
revolving pipe and curtain1 to close as 
much of the key-hole as possible4 ,but  
so far were all these precautions from  
being successful1 that a lock provided  
with all these appendages1 and affixed  
to the door of the ,united ,states      
,treasury at ,washington1 was picked4   
,the makers of locks have1 each one for 
himself1 contended against such         
difficulties as were known to them at   
the time of inventing their locks2 and1 
mortifying as failure may be1 it would  
be cowardly to yield up the enterprise  
whenever any new difficulty presented   
itself4 ,difficulties1 in locks as in   
other matters1 are made to be conquered4
  ,to shew how numerous are the sources 
of insecurity which have to be guarded  
against1 to meet the skill often brought
 to bear upon this lock1 we may adduce  
the reasons which led ,mr4 ,newell to   
apply a curtain to the key-hole of his  
lock4 ,supposing the interior           
arrangement of the triple set of        

tumblers1 and the metallic shielding    
wall1 to be perfect1 still1 if the first
 set of tumblers can be seen through the
 key-hole1 the following plan may be put
 in operation4 ,the under-side of the   
tumblers may be smoked1 by inserting a  
flame through the key-hole2 and the key 
will then leave a distinct mark upon    
each tumbler the next time it is used1  
shewing where it began to touch each    
tumbler in lifting it4 ,this may be seen
 by inserting a small mirror hinged into
 the lock through the key-hole4 ,there  
may even be an electric light used from 
a small portable battery1 to illumine   
the interior of the lock4 ,by these and 
other means the exact length of each bit
 of the key may be determined2 and from 
these data a false key may be made4 ,it 
is to prevent this inspection of the    
works1 or any other examination of an   
analogous kind1 that the revolving      
curtain was applied2 but1 as stated in  
the last paragraph1 even this did not   
suffice3 ingenuity devised a mode of    

baffling the contrivance of curtains as 
well as that of the wards and false     
notches in the tumblers4  ,when the     
parautoptic lock was completed1 it was  
keenly criticised in ,america1 owing to 
the long discussions respecting the     
merits of previous locks4 ,in a matter  
of this kind1 where a commercial motive 
would lead bankers and companies to     
apply a very severe test to the security
 of locks and similar fastenings to     
strong-rooms and receptacles1 any       
experiments made with their sanction    
became important4 ,mere letters or      
certificates emanating from individuals1
 expressive of opinions concerning a    
particular lock1 would be out of place  
in a volume relating to locks generally2
 but it is quite within the limits of   
the subject1 and has indeed become part 
of the history of locks1 to notice      
experiments and attempts of a more      
public character4 ,we may therefore     
introduce a few paragraphs of this      
description1 relating to the career of  

the ,american lock in ,america itself4  
,the principal bankers at ,boston       
7,u4,s47 held a meeting to take into    
consideration measures for testing the  
security of bank locks4 ,consequent on  
this meeting1 ,messrs4 ,day and ,newell 
deposited five hundred dollars with the 
cashier of the ,state ,bank at ,boston1 
to be by him paid to any one who could  
pick the parautoptic lock3 the trial was
 to be conducted under the auspices of  
the bank4 ,one of the locks was brought 
to the bank1 and was minutely examined  
by two machinists on two afternoons1    
after which it was secured to an iron   
chest1 and locked by a committee        
appointed by the bank4 ,the key was to  
remain in the hands of the committee    
during the trial2 and it was to be used 
at their discretion1 in unlocking and   
locking the door1 without the knowledge 
of either of the other parties--provided
 that in so doing no alteration was made
 in the combination-parts of the key4   
,ten days were allowed to the operators 

for the examination and the trial2 if   
they succeeded they were to have five   
hundred dollars2 but if they injured the
 lock they agreed to forfeit two        
hundred1 as a purchase price4 ,at the   
end of the period the lock remained     
unopened and uninjured2 and the two     
deposited sums were accordingly returned
 to the respective parties4  ,messrs4   
,page and ,bacon1 of ,st4 ,louis1 had a 
strong-room lock made by one of the     
chief locksmiths of that city4 ,to test 
its security1 the proprietors requested 
,mr4 ,hobbs to attempt to pick it2 he   
did so1 and succeeded4 ,whereupon the   
proprietors1 having purchased one of the
 parautoptic locks1 deemed it no more   
than fair play to subject this lock to a
 similar ordeal1 an additional zest     
being given by a reward of five hundred 
dollars offered by ,day and ,newell to  
the successful picker4 ,the maker of the
 former lock accepted the challenge2 he 
was allowed to examine the new lock     
piecemeal1 and was then allowed thirty  

days for his operations in picking4 ,he 
failed in the enterprise4 ,of course1 in
 this1 as in all similar cases1 the     
operator had not access to the true key4
  ,it follows from the nature of this   
lock1 as noticed in a former chapter1   
that when the bolt has been shot1 if the
 bits of the key be re-arranged in any  
other form1 the lock becomes to all     
intents and purposes a new lock1 so far 
as that key is concerned1 and cannot be 
unlocked unless the key revert to its   
original arrangement4 ,to test this     
principle1 a box with a parautoptic lock
 was placed in the room of the ,american
 ,institute in #ahde2 it was locked2 the
 bits of the key 7#ab in number7 were   
then re-arranged1 and the key was placed
 in the hands of any one who chose to   
try to open the lock--with the offer of 
a reward of five hundred dollars in the 
event of the lock being opened4 ,here1  
instead of the operator being called    
upon to devise new pick-lock implements1
 he had the actual key placed in his    

hands1 modified however in such a way   
that1 though the modifier could restore 
the original arrangement 7provided he   
had kept some kind of record71 the      
operator had numerous chances against   
his success4 ,the lock remained unopened
 notwithstanding this challenge4  ,we   
shall have occasion to shew presently1  
that if the number of tumblers 7and     
consequently the number of bits in the  
key7 be small--not exceeding six1 for   
instance--the possession of the true key
 gives any one the power of opening the 
lock1 provided he has time and patience 
to go through a few hundred changes of  
the bits of the key2 for1 as some one   
arrangement must have been that by which
 the lock was locked1 it must again     
occur if the user takes care to make all
 the arrangements in turn1 and tries the
 lock after each4 ,whether this         
constitutes picking a lock1 each        
lock-owner will decide for himself4 ,all
 that it is at present meant to state   
is1 that without access to the true key1

 the parautoptic lock has not hitherto  
been opened2 and that with the true but 
altered key the process of opening is   
possible1 but is slow and tedious4  ,in 
#ahdf the ,american ,institute appointed
 a committee to examine into the merits 
of the parautoptic lock4 ,on the #ahth  
of ,september in that year the          
,committee made their report1 signed by 
,professor ,renwick and ,mr4 ,t4 ,w4    
,harvey1 as follows3--  8,the ,committee
 of the ,american ,institute1 to whom   
was referred the examination of         
,,newell',s ,,parautoptic ,,bank ,,lock1
 report that they have given the subject
 referred to them a careful and         
attentive examination1 and have received
 full and complete explanations from the
 inventor4 ,they have remarked in the   
lock a number of important advantages1  
and1 in particular1 very great          
improvements upon the permutation-lock  
formerly submitted by him to the        
,american ,institute4 ,thus1 while it   
retains the advantages of the           

permutation principle1 combined with the
 property that the act of locking sets  
the slides to the particular arrangement
 of the bits in the skeleton key1 the   
parts thus set are completely screened  
from observation1 from being reached by 
false instruments1 or from being injured
 by any violence not sufficient to break
 the lock to pieces4  8,having in the   
course of their inquiries examined the  
different existing modes in which locks 
may be picked1 forced1 or opened by     
false keys1 the ,committee have come to 
the conclusion that the parautoptic lock
 cannot be opened by any of the methods 
now practised1 unless by a person in    
possession of the key by which it was   
locked1 in the exact form of combination
 in which it was used for the purpose1  
or in the almost impossible case of the 
bits being adjusted to the skeleton key 
by accident in that very form4 ,as the  
chances of such accidental combination  
range according to the number of movable
 bits1 from several thousands to several

 millions to one1 the ,committee do not 
conceive that so small a chance of      
success would ever lead to an attempt to
 profit by it4  8,in conclusion1 the    
,committee feel warranted in expressing 
the opinion1 that unless methods        
hitherto unknown or imagined should be  
contrived for the specific object1 the  
lock in question may be considered as   
affording entire and absolute security40
  ,the latest form which ,messrs4 ,day  
and ,newell have given to their         
challenge1 after the experience of the  
last few years1 is the following3       
8,first1 a ,committee of five gentlemen 
shall be appointed in the following     
manner3 viz4 two by the parties         
proposing to operate1 and two by        
ourselves2 and by the four thus         
appointed a fifth shall be selected4    
8,in the hands of this ,committee shall 
be placed ,two ,thousand ,dollars1 as a 
reward to the operator if successful in 
picking the lock by fair means4  8,we   
will place upon the inside of an iron   

door one of our best bank locks4 ,the   
operator shall then have the privilege  
of taking the lock from the door1 and   
have it in his possession for           
examination2 it shall then be returned  
to the ,committee for our inspection1 so
 that we may be assured that it has not 
been mutilated or injured4 ,the operator
 shall then1 in the presence of         
ourselves and the ,committee1 place the 
lock upon the door in its original      
position2 after which the ,committee    
shall place upon it their seals1 so that
 it cannot be removed or altered without
 their knowledge4 ,the lock being thus  
secured to the door1 we shall then be   
allowed to lock it up ourselves1 upon   
any change of which it is susceptible4  
8,the time for operation to continue    
thirty days2 and if at the end of that  
time he shall consider that he has made 
any progress towards picking the said   
lock1 he shall have thirty days more in 
which to continue operations40  ,the    
,austrian report concerning the         

,american lock was given in a former    
page1 to which we may here refer2 and   
then direct attention to ,england1 and  
to the discussions which have lately    
been carried on respecting the safety of
 locks4  ,it is of course natural that  
each inventor of a new lock should1     
while describing the product of his     
ingenuity1 point out what he conceives  
to be the imperfections of locks which  
have preceded3 use has sanctioned the   
custom not only with regard to locks1   
but also in other important matters4    
,hence there have been many 8lock       
controversies0 in ,england during the   
last seventy years4 ,we have seen how   
freely and justly the late ,mr4 ,bramah 
criticised all the locks that preceded  
his own2 and he was certainly not the   
man to shrink from criticism in his own 
case4 ,twenty years ago the ,bramah lock
 was itself made the subject of         
criticism4  ,mr4 ,ainger1 in his lecture
 on the subject delivered at the ,royal 
,institution1 ,london1 and afterwards in

 his article 8,lock0 in the ,encyclopdia
 ,britannica1 thus narrates the         
circumstances which led to the adoption 
of the false notches in the ,bramah lock
 as a means of security3 8,at length    
7after the original lock had acquired   
much celebrity17 an advertisement       
appeared in the public papers1          
requesting those who had lost keys of   
,bramah's locks1 not1 as had hitherto   
been done1 to break open their doors or 
drawers1 but to apply to the advertiser1
 who would undertake to save this       
destructive process by picking4 ,and it 
appeared that an individual of great    
dexterity could perform this operation  
almost with certainty4 ,the effect of   
this discovery on the demand for the    
locks may easily be imagined2 but the   
effect it had in stimulating ingenuity  
to provide a remedy is one of the best  
illustrations of the proverb1 that      
necessity is the mother of invention4   
,within a few days or weeks1 ,mr4       
,russell1 who was at that time employed 

in ,mr4 ,bramah's establishment1 devised
 an alteration which at once1 and       
without any expense1 entirely overcame  
the difficulty1 and converted the lock  
into one of perfect security4 ,this     
contrivance is the most simple and      
extraordinary that ever effected so     
important an object2 but before we      
describe it1 we will endeavour to       
explain what has been called the        
tentative process of lock-picking1 and  
which had been so successfully applied  
to ,bramah's locks40  ,mr4 ,ainger      
illustrates the subject by an           
engraving--not of an actual lock1 but of
 an hypothetical arrangement of bolts   
and notches2 and he then makes his      
reasoning apply to the actual process   
adopted by the picker of the real lock4 
8,a tendency to revolve was given with  
some force to the barrel2 then1 by means
 of a pair of small forceps1 the        
tumblers 7sliders7 were tried1 and it   
was ascertained which one was most      
detained by the pressure against the    

locking-plate4 ,that which offered most 
resistance was gradually depressed till 
its notch was felt to hang itself upon  
the locking-plate2 and so on till the   
whole were depressed in succession1     
exactly as they would have been         
depressed simultaneously by the key40   
,mr4 ,ainger then describes the         
contrivance which1 in his judgment1     
seemed to render any further attempts to
 pick the ,bramah lock hopeless4 ,this  
consisted in cutting false notches in   
the sliders2 so as to render it         
impossible for the picker to tell when  
he has brought a notch to the plane of  
the locking-plate1 whether it is a true 
notch1 or one of shallower depth1       
unfitted to admit the movement of the   
plate4  ,this is a very interesting     
statement1 for it shews that the        
mechanical or tentative method of       
opening was known in ,england long ago1 
although very little attention has been 
since paid to it4 ,in a complex ,bramah 
lock1 and in locks on the combination   

principle1 the difficulty of picking is 
almost insuperable1 so long as what may 
be termed the arithmetical method is    
adopted4 ,it is perfectly true1 as has  
been so often stated1 that the varied   
combinations in the arrangement of the  
slides amount to millions and even      
billions1 when the slides are in any    
degree numerous2 and if a person attempt
 to pick the lock by ringing the changes
 on all these combinations1 it would    
very likely require the lives of a dozen
 ,methuselahs to bring the enterprise to
 an end4 ,but by the mechanical method1 
sketched so clearly by ,mr4 ,ainger1 the
 exploit puts on a different aspect4    
,the experimenter passes through the    
keyhole an instrument so arranged as to 
give a tendency in the bolt to withdraw 
in the wished-for direction2 and a      
pressure produced in the slides by this 
tendency gives information concerning   
the state of the slides2 and then comes 
the tentative process on the slides     
themselves4 ,mr4 ,ainger was quite right

 in describing the false notches as an  
admirable addition to the safety of the 
,bramah lock2 but he was not correct in 
stating that these notches rendered any 
further attempts on the lock hopeless4  
,the false notches are not so deep as   
the true2 they will permit the barrel to
 turn partially but not wholly round4   
,but even supposing that the false notch
 had been hit upon in nearly every slide
 instead of the true1 and that the      
barrel had been partially turned to the 
extent which these notches permitted1   
there would then be a binding action at 
the false notches different from that in
 the true1 and this would guide the     
operator in his search for the true     
notches4 ,it would not add a new        
principle different from the one before 
in action1 but it would add to the time 
during which the search would have to be
 carried on4  ,we make these remarks in 
connection with ,mr4 ,ainger's article1 
which was probably written twenty years 
ago4 ,we now come to the year #ahej4    

,at the meeting of the ,institution of  
,civil ,engineers1 when ,mr4 ,chubb's   
paper was read1 many challenges and     
counter-challenges were made1 as to the 
possibility of picking certain locks4   
,mr4 ,chubb described1 among others1 a  
lock on the patent of ,mr4 ,davies1     
which1 ingenious though it be1 he       
considers not safe4 ,captain ,d4        
,o',brien differed from ,mr4 ,chubb in  
this matter2 he had had occasion to open
 from ten to twenty of ,davies's        
cabinet-locks daily1 during a period of 
two years1 and he never once observed   
the locks to be out of order2 in fact1  
they always appeared to afford great    
security4 ,mr4 ,chubb thereupon         
rejoined1 that he was prepared to       
produce a workman who would pick any    
number of ,davies' cabinet-locks1 of    
different combinations1 which he had    
never seen before1 taking only half an  
hour for each lock4  ,as another        
instance1 ,captain ,o',brien stated     
that1 in his capacity as ,inspector of  

,government ,prisons1 his attention had 
been much directed to the subject of    
secure locks2 and he produced1 among    
others1 specimens of those in use at the
 ,pentonville ,prison2 though not of    
first-rate workmanship1 he characterised
 them as being safe1 strong1 and cheap4 
,they were on ,thomas's principle4 ,the 
locks had been in use eight years1      
during which period not one had required
 to be replaced2 and any trifling       
derangements had been made good whilst  
the prisoners were at exercise4 ,mr4    
,chubb1 after making his offer          
concerning ,davies's lock1 stated that  
8he was willing to make the same offer  
with respect to the locks from the      
,pentonville ,prison2 and he might state
 that1 in point of security1 he         
considered them absolutely worthless20  
in proof of which he exhibited one of   
them1 and a common burglar's tool1 by   
which the lock could be opened with the 
greatest ease4  ,in respect to ,bramah's
 lock1 there was no particular challenge

 associated with the proceedings of the 
evening2 but incidental observations    
were made as to the degree of security  
pertaining to it4 ,mr4 ,farey1 after    
passing a high eulogium on the ingenuity
 of the principle and the beauty of the 
workmanship1 considered it nevertheless 
objectionable that the sliders should be
 so completely exposed to view4 ,he then
 proceeded to make the following        
observations3 8,it had been suggested1  
that a universal false key for ,bramah's
 locks might be made1 with the bottoms  
of its several notches formed by as many
 small steel sliders1 extending beyond  
the handle of the key1 so as to receive 
pressure from the fingers1 for moving   
each one of the sliders within the lock1
 with a sliding motion in its own       
groove1 independently of the other4     
,during such sliding motion1 a gentle   
force could be exerted1 tending to turn 
the barrel round4 ,under such           
circumstances1 supposing that the motion
 of the barrel was prevented by any one 

slider only2 that one1 having to resist 
all the turning force1 would be felt to 
slide more stiffly endways in its       
groove1 and therefore it could be felt  
when its unlocking notch arrived        
opposite the steel plate1 and left some 
other slider to begin to resist the     
turning force4 ,such a circumstance     
7continues ,mr4 ,farey7 presumes a      
palpable inaccuracy in the radiating    
correspondence between the notches in   
the steel plate and the grooves for the 
sliders in the barrel1 which could not  
happen with ,bramah's workmanship40#f   
,he further remarked3 8,unfortunately1  
if a ,bramah's key fell into dishonest  
hands1 even for a short time1 an        
impression could be easily taken1 and a 
false key as easily made4 ,a            
turkey-quill1 notched into the form of a
 key1 had sufficed to open a ,bramah's  
lock2 and an efficient false key could  
be formed out of a pocket pencil-case4  
,such facility of fabrication was an    
invitation to dishonesty2 and as an     

abortive attempt left no trace1 the     
impunity was an encouragement to repeat 
the attempt until success is attained40 
#f ,see also ,mr4 ,owen's suggestion1 p4
 #ei1 ante4  ,with respect to ,chubb's  
locks1 a discussion arose out of a      
statement made by ,mr4 ,hodge4 ,mr4     
,chubb had himself stated it to be a    
general opinion that a skilful workman1 
furnished with impressions taken from   
the true key1 in wax or soap1 could make
 a false key to open any lock2 and he   
considered that1 in common locks1 with  
the most elaborate wards1 but with only 
one tumbler1 as also in ,bramah's locks1
 there was much truth in the notion4 ,in
 respect to his own lock1 however1 with 
six double-acting tumblers1 8a false key
 made ever so carefully from impressions
 would not be likely to open the lock1  
for want of exactitude in the lengths of
 the several steps2 and if the key could
 not be made exact from the impressions1
 there would be no chance of rectifying 
it by trial in the lock1 on account of  

the total uncertainty as to which part  
required alteration40 ,mr4 ,hodge stated
 that1 in ,america1 he had repeatedly   
seen impressions taken of locks having  
twelve or fourteen tumblers1 in         
consequence of the bellies of the       
tumblers1 when at rest1 coinciding with 
the form of the key 7see page #fc74 ,he 
also suggested a method of taking an    
impression of the bellies of the        
tumblers2 but ,mr4 ,chubb1 ,mr4 ,farey1 
,mr4 ,stephenson1 and ,mr4 ,whitworth1  
all expressed a disbelief that a        
,chubb's lock could be opened by the    
means indicated by ,mr4 ,hodge4 ,mr4    
,hodge admitted that he was not aware of
 any lock actually made by ,messrs4     
,chubb having been picked in ,america2  
but that the locks to which he had      
adverted were such exact imitations1    
that he had no doubt of the ,chubb lock 
yielding to similar treatment4 ,he      
further stated that there were persons  
in ,new ,york who would undertake to    
pick a real ,chubb lock4     ,,chapter  

,,ix4  ,,the ,,lock ,,controversy3      
,,during ,,and ,,since ,,the ,,time ,,of
 ,,the ,,great ,,exhibition4   ,we next 
come to the remarkable year #ahea1 which
 produced so many unexpected results in 
connection with the industrial display  
in ,hyde ,park1 and conferred a lasting 
benefit on the useful arts and          
manufactures of the ,united ,kingdom1 by
 bringing their products into contrast  
and competition with those of other     
nations4 ,it was to be expected that    
such a trial as this would afford       
evidences of national failure as well as
 of success2 but probably no one        
suspected before the trial1 that        
,english locks1 so celebrated over the  
greater part of the world for skilful   
mechanical design1 beauty of            
workmanship1 and perfect inviolability1 
would readily yield to a well-arranged  
system of lock-picking4 ,such1 however1 
was the case2 and we are bound to admit 
that ,mr4 ,hobbs1 the author of this    
system1 is a mechanician of great skill1

 and with a profound knowledge of the   
art of the locksmith4  ,the first step  
in the celebrated lock controversy of   
#ahea was taken by ,mr4 ,hobbs himself1 
who declared to a party of scientific   
men in the ,crystal ,palace1 that all   
the locks made in this country up to    
that date admitted of being very easily 
picked2 and in order to explain to these
 gentlemen the principle upon which this
 was to be done1 ,mr4 ,hobbs picked one 
of ,chubb's patent detector-locks in    
their presence in a few minutes4  ,the  
fairness of this experiment having been 
called in question by certain persons   
who were not present at the time when it
 was made1 ,mr4 ,hobbs1 on ,july #bast1 
#ahea1 wrote a letter from the ,american
 department of the ,great ,exhibition1  
to ,messrs4 ,chubb1 simply announcing   
that an attempt would be made1 on the   
next following day1 to pick a lock      
manufactured by them1 and which was at  
that time on the door of a strong room  
in a house named by ,mr4 ,hobbs4        

,messrs4 ,chubb were invited to be      
present at the operation2 but no member 
of the firm attended4 ,what occurred on 
the day specified may best be given in  
the words of a letter written by those  
who witnessed the operation4            
8,london1 ,july #bb1 #ahea4  8,we the   
undersigned hereby certify1 that we     
attended1 with the permission of ,mr4   
,bell1 of ,no4 #cd ,great               
,george-street1 ,westminster1 an        
invitation sent to us by ,a4 ,c4 ,hobbs1
 of the ,city of ,new ,york1 to witness 
an attempt to open a lock throwing three
 bolts and having six tumblers1 affixed 
to the iron door of a strong-room or    
vault1 built for the depository of      
valuable papers1 and formerly occupied  
by the agents of the ,south-,eastern    
,railway2 that we severally witnessed   
the operation1 which ,mr4 ,hobbs        
commenced at #ce minutes past #aa       
o'clock ,a4,m41 and opened the lock     
within #be minutes4 ,mr4 ,hobbs having  
been requested to lock it again with his

 instruments1 accomplished it in the    
short space of #g minutes1 without the  
slightest injury to the lock or door4   
,we minutely examined the lock and door 
7having previously had the assurance of 
,mr4 ,bell that the keys had never been 
accessible to ,mr4 ,hobbs1 he having had
 permission to examine the key-hole     
only74 ,we found a plate at the back of 
the door with the following inscription3
 #8,chubb's ,new ,patent 7,no4          
#bfa1dfa71 ,st4 ,paul's ,churchyard1    
,london1 ,maker to ,her ,majesty4'0     
,this letter was signed with the names  
and addresses of the following          
gentlemen3--    ,mr4 ,handley4          
,mr4 ,t4 ,shanks4      ,william         
,marshall4       ,colonel ,w4 ,clifton4 
,w4 ,armstead4            ,mr4 ,elijah  
,galloway4      ,g4 ,r4 ,porter4#g      
,paul ,r4 ,hodge4      ,f4 ,w4 ,wenham4 
,charles ,h4 ,peabody4      ,a4 ,shanks4
    #g ,late ,secretary to the ,board of
 ,trade4  ,several of these names are   
well and publicly known in ,england and 

the ,united ,states4  ,this event gave  
rise to much newspaper controversy2 and 
attempts were made to shew that1 as this
 was not a test lock1 prepared expressly
 for challenge1 the picking proved      
nothing as regards the finest of the    
manufacturers' locks4 ,two              
circumstances1 however1 have to be      
noticed--that the lock was of sufficient
 commercial importance to be placed on a
 door enclosing valuable papers1 and    
that the makers had an opportunity to   
attend and witness1 and comment on the  
trial1 if they so chose4 ,we may here   
remark1 that one of the ingenious       
contrivances of the ,chubb lock1 the    
detector1 excited some doubt no less    
than fifteen years ago1 as will be seen 
from the following4 ,the writer of the  
article 8,lock0 in ,hebert's ,engineers'
 and ,mechanics' ,encyclopdia1 while    
speaking with much commendation of      
,chubb's locks1 points out a curious    
feature1 which seems to him to render   
somewhat doubtful the surety of the     

detector apparatus4 8,in ,barron's and  
,bramah's locks10 he observes1 8the     
picker has no means of knowing whether  
the tumblers are lifted too high or not2
 but in ,chubb's he has only to put the 
detector hors de combat in the first    
instance1 by a correct thrust from the  
outside of the door 7which might be     
accurately measured71 so as to fix it   
fast in its place2 the detector then    
becomes a stopper to the undue ascent of
 the tumblers1 and the extent of their  
range is thereby correctly ascertained4 
,thus1 it appears to us1 the detector   
might be converted into a director of   
the means for opening the lock40  ,much 
will depend on the view which is taken  
of the circumstance just noted4 ,the    
object of the detector is1 not to       
prevent the lock from being picked1 but 
to shew that an attempt has been made to
 pick it2 or1 at least1 to attain a     
given purpose by an indirect instead of 
a direct method4 ,but if there be really
 any truth in the surmise1 that the     

detector actually guides a skilful hand 
in determining how high the tumblers    
should be raised1 the supposed advantage
 will be purchased at rather a dear     
rate4 ,as we are here1 however1 speaking
 of facts and not of mere opinions1 it  
is proper to say1 that the lock opened  
by ,mr4 ,hobbs had the detector         
apparatus1 but that it was not disturbed
 by him in picking the lock4  ,but      
instead of reiterating opinions1 we will
 state the method by which most of the  
tumbler-locks made in ,england1 up to   
the date of the ,great ,exhibition1 can 
be opened or picked4  ,bearing in mind  
the principle on which the picking of   
locks is said to depend1 namely1 that   
8whenever the parts of a lock which come
 in contact with the key are affected by
 any pressure applied to the bolt1 or to
 that portion of the lock by which the  
bolt is withdrawn1 in such a manner as  
to indicate the points of resistance to 
the withdrawal of the bolt1 such a lock 
can be picked10 the first step is to    

produce the requisite pressure4         
,illustration3 fig4 #di4  ,if the end of
 the bolt were exposed1 this pressure   
might be applied by some force tending  
to shoot back the bolt2 but as the bolt1
 whenever it is shot1 is buried in the  
jamb of the door1 or otherwise concealed
 from view1 the pressure can in general 
only be applied through the key-hole4   
,in order1 therefore1 to apply this     
pressure1 the operator provides himself 
with an instrument capable of reaching  
the talon of the bolt1 which in the case
 of the ,chubb lock was a pipe-key of   
the form shewn at a b1 fig4 #di1        
furnished at the pipe-end with that     
portion of the bit of the key b c which 
moves the bolt 7see fig4 #cb1 page #eg1 
where the step which acts on the bolt is
 called the terminal step74 ,the other  
end of the pipe-key is made square1 as  
at a1 for the purpose of receiving the  
square eye e of the lever e f1 fig4 #ej1
 to the further end of which f a weight 
w is attached by means of a string s4   

,now it is evident that if this pipe be 
introduced into the lock as far as it   
will go1 and be turned round as in the  
act of unlocking1 and the lever and     
weight be attached to the end a1 the bit
 b c of the pipe-key will maintain a    
permanent pressure on the bolt1 which1  
if the weight be sufficient1 will throw 
back the bolt as soon as the tumblers   
are raised to the proper height to allow
 the stump to pass4  ,illustration3 fig4
 #ej4  ,the next step in the operation  
is to raise the tumblers to the proper  
height4 ,for this purpose a second pipe 
m n is made to slide upon the first with
 an easy motion1 and by means of the    
cross handle h h can be turned round or 
slid backwards and forwards on the tube 
a b4 ,this tube m n is also furnished   
with a single projecting bit or step n  
o1 corresponding with one of the six    
steps of the key1 fig4 #cb1 and made of 
the proper length for entering the      
key-hole4  ,now for the operation of    
opening a tumbler-lock with this simple 

apparatus4 ,referring to fig4 #ca1 page 
#ef1 it will be evident that if the pipe
 a b1 fig4 #di1 be passed over the pin  
of the lock and turned round towards the
 left1 and the weight be attached1 there
 will be a tendency in the bolt to shoot
 back1 which tendency will bring the    
stump s1 fig4 #ca1 up against the inner 
angle or shoulder of one or other of the
 tumblers1 whichever happens to project1
 however slightly2 or1 as ,mr4 ,hobbs   
expresses it1 8one or more of the       
tumblers will bind40 ,by moving forward 
the pipe m n and turning round the bit n
 o in the lock1 it is easy to ascertain1
 by delicate touch1 which of the        
tumblers it is that binds4 ,it may be   
found that all are free to move except  
one or two against which the stump is   
pressing with the force of the weight w1
 fig4 #ej4 ,the bit n o is therefore    
brought gently under the bellies of the 
tumblers which bind1 and they are moved 
slightly upwards until they cease to    
bind4 ,as soon as they are set free     

another tumbler will bind2 that is1 the 
bolt will move through a small space1 so
 as to bring the stump into contact with
 that particular tumbler which now      
projects2 this in its turn is relieved1 
another tumbler binds and is relieved1  
and so on until the tumblers are1 one by
 one1 raised to the proper height for   
the stump to pass4 ,when the last       
binding tumbler is raised to the proper 
height1 the weight w being no longer    
resisted1 shoots the bolt back1 and the 
work is done4  ,now it must be evident  
that in this operation the detector     
apparatus need not come into operation4 
,but if1 as has been proposed1 a        
detector-spring be added to each        
tumbler1 it may be converted into a     
friend or a foe according to the use    
that is made of it4 ,if the tumblers are
 lifted too high1 they will be detained 
or detected in that position1 and the   
operator will have to release them by   
turning the bit round in the opposite   
direction before he can begin his work  

again4 ,the same force1 however1 which  
detains the tumblers when they are      
lifted too high will obviously detain   
them when they are lifted only just high
 enough1 and thus the detector-springs  
would really be of great assistance to  
the operator in picking such a          
tumbler-lock4  ,the apparatus which we  
have described for picking the          
tumbler-lock must be varied to suit the 
form of key employed in opening the     
lock2 but it is not difficult1 in the   
case of most locks1 to ascertain this   
form through the key-hole1 without      
examining the key itself4  ,it is but   
fair to state in this place1 that since 
the above method of picking             
tumbler-locks was made known1#h ,mr4    
,chubb has added a series of teeth and  
notches to the stump and tumblers2 the  
effect of which would evidently prevent 
the application of the above method of  
picking1 because any permanent pressure 
applied to the bolt would send a tooth  
of the stump into a notch of the        

tumbler1 and prevent all further motion4
 ,but recurring to the principle1 that  
whenever the parts of a lock which come 
in contact with the key indicate the    
points of resistance when any pressure  
7whether permanent or temporary7 is     
applied in attempting to withdraw the   
bolt1 that lock can be picked1 it       
follows1 if this principle be admitted1 
that although the notches prevent the   
application of the form of instrument   
described1 yet there is sufficient      
indication afforded by the pressure to  
enable a skilful operator1 with proper  
instruments1 to form a false key1 as was
 done in the case of the lock referred  
to at page #ajd4 ,we now proceed to the 
second stage in the lock controversy of 
#ahea4    #h ,we believe the method was 
first made publicly known at a special  
general meeting of the members of the   
,institution of ,mechanical             
,engineers1 held at the rooms of the    
,society of ,arts1 ,london1 on the      
#cjth ,june1 #ahea1 when a paper was    

read by ,mr4 ,paul ,r4 ,hodge 8,on the  
progress of improvements in locks in the
 ,united ,states of ,america40 ,a       
report of this paper1 together with the 
discussion thereon1 was   published by  
,waterlow and ,sons1 ,london ,wall1     
#ahea4 ,plate #cd 7figs4 #i   and #aj7  
of this report contains representations 
of the lock-picking   apparatus1 from   
which we have copied our figures4  ,soon
 after the picking of the ,chubb lock in
 ,great ,george-street1 and consequent  
on the excitement and discussion to     
which that operation led1 a committee1  
consisting of ,mr4 ,g4 ,rennie1         
,professor ,cowper1#i and ,dr4 ,black1  
agreed to superintend the arrangements  
for a more severe testing of ,mr4       
,hobbs's power to open locks4 ,there had
 been for many years exhibited in the   
window of ,messrs4 ,bramah's shop1 in   
,piccadilly1 a padlock of great         
complexity and beauty2 to which an      
announcement was affixed1 that a reward 
of two hundred guineas would be given to

 any person who should succeed in       
picking that lock4 ,this challenge was  
accepted by ,mr4 ,hobbs2 and the        
committee managed all the arrangements1 
as arbitrators between ,mr4 ,hobbs on   
the one side and ,messrs4 ,bramah on the
 other4 ,the lock was removed to an     
upper room in ,messrs4 ,bramah's        
establishment2 where it was placed      
between two boards1 and so fixed and    
sealed1 that no access could be obtained
 to any part of it except through the   
key-hole4 ,the room was to be given up  
to ,mr4 ,hobbs2 he was not to be        
interrupted by the presence or entrance 
of any other persons2 and he was allowed
 a period of thirty days for opening the
 lock4 ,if the lock was not picked at   
the expiration of that period1 ,mr4     
,hobbs was to be considered as having   
failed in his attempt4    #i ,in        
mentioning the name of the late         
,professor ,edward ,cowper1 we   cannot 
refrain from deploring the loss which   
mechanical science has   suffered by his

 too-early death4 ,the application of   
mechanical   principles to manufactures 
was treated by him in his lectures and  
illustrations with a felicity which has 
been rarely equalled4  ,there was much  
negotiation and correspondence before   
and during ,mr4 ,hobbs's operation on   
this lock4 ,on ,july #b1 he1 with a view
 to this enterprise1 applied for        
permission to take wax impressions of   
the key-hole4 ,this permission being    
given1 and the parties having met to    
discuss the necessary arrangements1 an  
agreement was signed on the #aith1      
reciting the terms of the challenge1 and
 providing that thirty days should be   
allowed to ,mr4 ,hobbs to effect his    
enterprise2 that the lock should be     
secured in a certain specified way2 and 
that the key should remain in the       
possession of ,messrs4 ,bramah1 who were
 to retain the right of using it in the 
lock when ,mr4 ,hobbs was not at work4  
,messrs4 ,bramah subsequently           
relinquished this last-mentioned        

privilege1 in order that the trial might
 be perfectly fair2 and it was agreed   
that the key should be sealed up during 
the whole period1 beyond the reach      
either of ,mr4 ,hobbs or ,messrs4       
,bramah2 and that the key-hole should be
 secured by an iron band1 sealed1 when  
,mr4 ,hobbs was not at work4 ,these and 
other conditions were embodied in the   
agreement noticed in the last paragraph4
  ,mr4 ,hobbs commenced his labours on  
,july #bdth4 ,after a few visits to the 
lock1 ,messrs4 ,bramah wished to have   
the privilege of inspecting it1 or else 
that such an inspection should be made  
by the arbitrators2 and1 during a       
correspondence which arose out of this  
request1 the operations were suspended4 
,mr4 ,hobbs resumed his work on ,august 
#af4 ,on the #bc;d1 ,messrs4 ,bramah    
drew the attention of the arbitrators to
 the challenge1 that the reward of two  
hundred guineas was offered to the      
artist who should make an instrument    
that would pick or open the lock2 that  

he was to be paid the money on the      
production of the instrument2 and that1 
unless some person were present1 it was 
impossible that any one could know that 
the lock had been opened by the         
instrument which might be produced4     
,this letter was not allowed by the     
arbitrators to affect the arrangements  
made4 ,we may now consistently give the 
8,report of the ,arbitrators40          
8,whereas for many years past a padlock 
has been exhibited in the window of     
,messrs4 ,bramah's shop1 in ,piccadilly1
 to which was appended a label with     
these words3 #8,the artist who can make 
an instrument that will pick or open    
this lock shall receive two hundred     
guineas the moment it is produced2' and 
,mr4 ,hobbs1 of ,america1 having        
obtained permission of ,messrs4 ,bramah 
to make trial of his skill in opening   
the said lock1 ,messrs4 ,bramah and ,mr4
 ,hobbs severally agreed that ,george   
,rennie1 ,esq41 ,f4,r4,s41 of ,london2  
and ,professor ,cowper1 of ,king's      

,college1 ,london2 and ,dr4 ,black1 of  
,kentucky2 should act as arbitrators    
between the said parties4  8,that the   
trial should be conducted according to  
the rules laid down by the arbitrators1 
and the reward of two hundred guineas be
 decided by them2 in fine1 that they    
should see fair play between the        
parties4  8,on ,july #bc it was agreed  
that the lock should be enclosed in a   
block of wood1 and screwed to a door1   
and the screws sealed1 the key-hole and 
the hasp only being accessible to ,mr4  
,hobbs2 and1 when he was not operating1 
the key-hole was to be covered with a   
band of iron and sealed by ,mr4 ,hobbs1 
that no other person should have access 
to the key-hole4 ,the key was also      
sealed up1 and was not to be used until 
,mr4 ,hobbs had finished his operations4
 ,if ,mr4 ,hobbs succeeded in picking or
 opening the lock1 the key was to be    
tried2 and if it locked and unlocked the
 padlock1 it should be considered as a  
proof that ,mr4 ,hobbs had not injured  

the lock1 but had fairly picked or      
opened it1 and was entitled to the two  
hundred guineas4  8,on the same day1    
,july #bc1 ,messrs4 ,bramah gave notice 
to ,mr4 ,hobbs that the lock was ready  
for his operations4  8,on ,july #bd ,mr4
 ,hobbs commenced his operations2 and on
 ,august #bc ,mr4 ,hobbs exhibited the  
lock opened to ,dr4 ,black and          
,professor ,cowper 7,mr4 ,rennie being  
out of town74 ,dr4 ,black and ,mr4      
,cowper then called in ,mr4 ,edward     
,bramah and ,mr4 ,bazalgette1 and shewed
 them the lock opened2 they the         
last-named two gentlemen are of course  
meant then withdrew1 and ,mr4 ,hobbs    
locked and unlocked the padlock in      
presence of ,dr4 ,black and ,mr4        
,cowper4  8,between ,july #bd and ,aug4 
#bc ,mr4 ,hobbs's operations were for a 
time suspended2 so that the number of   
days occupied by ,mr4 ,hobbs was        
sixteen1 and the number of hours he was 
actually in the room with the lock was  
fifty-one4  8,on ,friday1 ,aug4 #bi1    

,mr4 ,hobbs again locked and unlocked   
the padlock in presence of ,mr4 ,g4     
,rennie1 ,professor ,cowper1 ,dr4       
,black1 ,mr4 ,edward ,bramah1 ,mr4      
,bazalgette1 and ,mr4 ,abrahart4  8,on  
,saturday1 ,aug4 #cj1 the key was tried1
 and the padlock was locked and unlocked
 with the key1 by ,professor ,cowper1   
,mr4 ,rennie1 and ,mr4 ,gilbertson2 thus
 proving that ,mr4 ,hobbs had fairly    
picked the lock without injuring it4    
,mr4 ,hobbs then formally produced the  
instruments with which he had opened the
 lock4  8,we are1 therefore1 unanimously
 of opinion1 that ,messrs4 ,bramah have 
given ,mr4 ,hobbs a fair opportunity of 
trying his skill1 and that ,mr4 ,hobbs  
has fairly picked or opened the lock2   
and we award that ,messrs4 ,bramah and  
,co4 do now pay to ,mr4 ,hobbs the two  
hundred guineas4    ,,george ,,rennie1  
,chairman4   ,,edward ,,cowper4   ,j4   
,r4 ,,black4    ,holland ,street1       
,blackfriars1   ,sept4 #b1 #ahea40  ,it 
may be here stated1 in reference to the 

space of time during which the          
operations were being conducted1 that   
the actual opening of the lock occurred 
much earlier1 so far as concerned the   
principle involved1 though not in a way 
to meet the terms of the challenge4 ,on 
his fifth visit1 ,mr4 ,hobbs succeeded  
in adjusting the slides and moving the  
barrel1 preparatory to withdrawing the  
bolt2 but the instrument with which the 
barrel was to be turned round1 being too
 slight1 slipped1 and defeated the      
operation4 ,mr4 ,hobbs had then to      
readjust the barrel1 and to make a new  
instrument to aid him2 this new         
instrument1 when completed1 enabled him 
to open the lock in the space of an hour
 or two4  ,on the same day ,messrs4     
,bramah addressed a letter to the       
arbitrators1 stating the reasons which  
induced them to think that1 though ,mr4 
,hobbs had succeeded in opening the     
lock1 the manner of doing so did not    
come within the meaning of the challenge
 originally made by them4 ,the          

arbitrators1 however1 were unanimous in 
their award1 and ,messrs4 ,bramah bowed 
to it4  ,in an article written in one of
 the daily newspapers immediately after 
the opening of the lock1 the following  
notice was given of the lock and its    
production3 8,we were surprised to find 
that the lock which has made so much    
noise in the world is a padlock of but  
#d inches in width1 the body of it #a   
inches thick1 and its thickness over the
 boss #b inches4 ,upon opening the outer
 case of the lock1 the actual barrel    
enclosing the mechanism was found to be 
#b inches in length and #a inches in    
diameter4 ,the small space in which the 
works were confined1 and its snug1      
compact appearance was matter of        
astonishment to all present4 ,the lock  
and key were made forty years since by  
the present head of the eminent firm of 
,messrs4 ,maudslay and ,co41 ,mr4       
,maudslay being at that time a workman  
in the employ of ,mr4 ,bramah40  ,we may
 here remark1 as indeed has been        

remarked in former pages1 that the      
,bramah lock is1 and will probably      
continue to be1 deservedly celebrated   
for the amount of mechanism contained in
 a small space1 as adverted to in the   
last paragraph4 ,the cylindrical form is
 well calculated for this concentration 
of power within narrow limits2 and the  
smallness of the key is a great merit4  
,the objections made by ,messrs4 ,bramah
 to the award of the committee were     
embodied in the following letter to ,mr4
 ,rennie1 dated #ith ,september3        
8,,dear ,,sir1--,we beg to acknowledge  
your letter of yesterday's date1 and    
will not trouble you to attend here     
to-morrow1 but beg to hand you the      
#bajl4 awarded by the arbitrators to    
,mr4 ,hobbs4 ,we need scarcely   repeat 
that the decision at which the          
arbitrators have arrived has   surprised
 us much2 and we owe it to ourselves and
 the public to   protest against it4 ,we
 do so for the following reasons3       
8#a4 ,because the arbitrators1 having   

been appointed to see fair-play1   and  
that the lock was fairly operated upon1 
did not1 although   repeatedly requested
 in writing to do so1 once inspect or   
allow any   one to witness ,mr4 ,hobbs's
 operations during the sixteen days he  
had   the sole custody of the lock and  
was engaged in the work4    8#b4        
,because the arbitrators did not once   
exercise their right of using   the key1
 although repeatedly requested in       
writing to do so1 till after   ,mr4     
,hobbs had completed his operations2 and
 then1 instead of applying   at once to 
prove that no damage had been done to   
the lock1 allowed him   twenty-four     
hours to repair any that might have     
occurred4    8#c4 ,because the lock     
being opened by means of a fixed        
apparatus   screwed to the wood-work in 
which the lock was enclosed for the     
purpose of experiment 7which it is      
obvious could not have been applied   to
 an iron door without discovery71 and   
the addition of three or four   other   

instruments1 the spirit of the challenge
 has evidently not been   complied with4
    8#d4 ,because from the course       
adopted an opportunity of some good     
scientific results has been taken from  
us2 as neither arbitrators nor   any one
 else saw the whole or even the most    
important instruments1 by   which it is 
said the lock was picked1 actually      
applied in operation1   either before or
 after the lock was presented open to   
the arbitrators4    8#e4 ,because during
 the progress of ,mr4 ,hobbs's          
operations1 and several   days before   
their completion1 we called the         
attention of the   arbitrators to what  
we considered the interpretation of the 
challenge1   begging at the same time   
that they would apply the key and       
appoint   some one to be present during 
the residue of the experiment2 feeling  
that whatever might be the result in a  
scientific point of view1 the   reward  
could not be awarded4    8,we would add1
 that we think that several points which

 appear in your   minutes should not    
have been mentioned in your award2 more 
especially   that ,mr4 ,hobbs on the    
#b;d of ,june took a wax-impression of  
the lock1   and had made1 as far as he  
could1 instruments therefrom between    
that   date and the commencement of his 
operations4    8,we are1 dear sir1      
8,your obedient servants1    8,,bramah  
,,and ,,co40  ,in order that the        
opinions of ,messrs4 ,bramah and others 
may be given with as much fairness as   
possible1 on a matter which they could  
not feel but otherwise than important to
 them1 we may state1 that among the     
letters to which the picking of the     
,bramah lock gave rise in the public    
journals1 was the following addressed to
 the ,observer newspaper on #ajth       
,october3    8,,sir1--,this controversy 
having excited an unusual degree of     
public   attention for some time past1  
perhaps you will be good enough to allow
   us to state in your journal1 that the
 lock on which ,mr4 ,hobbs operated     

had not been taken to pieces for many   
years1 and it was only on   examining it
 7after the award of the committee7 that
 we discovered the   startling fact1    
that in no less than three particulars  
it is inferior   to those we have made  
for years past4 ,the lock had remained  
so long in   its resting-place in our   
window that the proposal of ,mr4 ,hobbs 
somewhat surprised us4 ,after his       
appearance1 however1 no alteration      
could of course be made without our     
incurring the risk of being   charged   
with preparing a test-lock for the      
occasion2 we were therefore   bound in  
honour to let the lock remain as ,mr4   
,hobbs found it when he   accepted the  
challenge4 ,no one inspected his        
operations during the   sixteen days he 
had the sole custody of the lock and was
 engaged at   the work4 ,we are         
therefore compelled to advertise another
 #bjj guineas1   in order that we may   
see the lock operated upon and opened1  
if it be   possible2 and thus gain such 

information as would enable us to use   
means that would defy even the          
acknowledged skill of our ,american     
friends4 ,we believe the ,bramah lock to
 be impregnable2 and we cannot   open it
 ourselves1 with the knowledge ,mr4     
,hobbs has given us4 ,we have   fitted  
up the same lock with such improvements 
as we now use1 and some   trifling      
change suggested by the recent trial1   
and restored it with   its challenge to 
our window4 ,we have not done this in a 
vain1 boasting   spirit2 on the         
contrary1 we feel it rather hard that1  
from the way in   which the former trial
 was conducted1 we are driven to adopt  
this   course4 ,had any one inspected   
,mr4 ,hobbs's operations during that    
trial1 it would not have been necessary4
    8,we are1 sir1 c41    8,,bramah     
,,and ,,co40  ,messrs4 ,bramah are well 
entitled to offer any explanation       
concerning the relative perfection of   
the lock in question1 and of one that   
they could now produce with certain     

improvements in some parts of the       
working mechanism2 but if these         
improvements do not involve any new     
invention1 patented or otherwise1--that 
is1 if the lock be really a carrying out
 of the contrivances already made       
public1--it is difficult to see why it  
should not yield to the same treatment  
as the other4 ,it is true that1 shortly 
after the decision of the arbitrators1  
,messrs4 ,bramah exhibited a new lock in
 their window1 and repeated their       
challenge in the same terms as before1  
with the single addition1 that          
applications were to be made in writing 
only4 ,we have reason to know that an   
application was made1 and that the      
consequence was the withdrawal of the   
challenge4 ,in respect to the actual    
contest1 however1 the character and     
position of the arbitrators ought surely
 to hold ,mr4 ,hobbs justified in his   
proceedings4 ,they were not all         
,americans 7supposing nationality to    
give a bias in the matter72 two were    

,englishmen1 both of distinguished rank 
in respect to mechanical knowledge2 and 
as ,mr4 ,hobbs was as much bound by     
their decision as ,messrs4 ,bramah1 he  
was entitled to claim any advantage     
resulting from a favourable decision4   
,the following is a description1 so far 
as can be given in words1 of the mode in
 which ,mr4 ,hobbs operated on the      
,bramah lock4 ,the first point to be    
attained was to free the sliders from   
the pressure of the spiral spring2 the  
spring was very powerful1 pressing with 
a force of between #cj and #dj lbs42 and
 until this was counteracted1 the       
sliders could not be readily moved in   
their grooves4 ,a thin steel rod1       
drilled at one end1 and having two long 
projecting teeth1 was introduced into   
the key-hole and pressed against the    
circular disc between the heads of the  
sliders2 the disc and spring were       
pressed as far as they would go4 ,in    
order to retain them in this position1 a
 curved stanchion was screwed into the  

side of the boards surrounding the lock1
 and the end brought to press upon the  
steel rod1 a thumb-screw passing through
 the drilled portion of the instrument  
and keeping it in its place4 ,the       
sliders being thus freed from the action
 of the spring1 operations commenced for
 ascertaining their proper relative     
positions4 ,a plain steel needle1 with a
 moderately fine point1 was used for    
pushing in the sliders2 while another   
with a small hook at the end1 something 
like a crochet-needle1 was used for     
drawing them back when pushed too far4  
,by gently feeling along the edge of the
 slider1 the notch was found and        
adjusted1 and its exact position was    
then accurately measured by means of a  
thin and narrow plate of brass1 the     
measurements being recorded on the brass
 for future reference4 ,the operator was
 thus enabled1 by this record1 to       
commence each morning's work at the     
point where he left off on the previous 
day4 ,the lock having eighteen sliders1 

the process of finding the exact        
position of the notch in each was       
necessarily slow4 ,mr4 ,hobbs employed a
 small bent instrument to perform the   
part of the small lever or bit of the   
key2 with this he kept constantly       
pressing on the cylinder which moved the
 bolt4 ,he thus knew that if ever he got
 the slide-notches into the right place1
 the cylinder would rotate and the lock 
open4 ,he could feel the varying        
resistance to which the sliders were    
subjected by this tendency of the       
cylinder to rotate2 and he adjusted them
 one by one until the notch came        
opposite the steel plate4 ,the false    
notches added1 of course1 much to his   
difficulty2 for when he had partially   
rotated the cylinder by means of the    
false notches1 he had to begin again to 
find out the true ones4  ,this          
description accords pretty nearly with  
that given in a former page2 but we     
reproduce it here to shew not merely    
what might be the process adopted1 but  

what really has been done4 ,one         
circumstance ought at least to be noted 
in these transactions--there is no      
mystery2 the method adopted is the      
result of a process of reasoning        
candidly and openly explained4  ,in     
justice to ,messrs4 ,bramah we thought  
it our duty to give them an opportunity 
of stating what improvements they had   
made in their locks since the date of   
the ,great ,exhibition2 and accordingly1
 on the #bhth ,april1 #ahec1 our        
publisher addressed to ,messrs4 ,bramah 
a note1 stating that a ,rudimentary     
,treatise on the ,construction of ,locks
 was being prepared1 and inviting them  
to contribute thereto4 ,the following is
 a copy of their reply3    8#abd        
,piccadilly1 ,may #b;d1 #ahec4          
8,,sir1--,pressure of business has      
prevented our sending an earlier reply  
to your favour of the #bhth ult4        
8,the lock on which ,mr4 ,hobbs operated
 during the ,great ,exhibition had      
been made nearly forty years1 and when  

taken to pieces the sliders   were found
 to be in iron1 instead of steel2 and   
the key-hole of the   lock being three  
times larger than it ought to have been1
 enabled the   operator to fix down the 
spring of the lock1 and yet leave       
himself   ample space to turn and bend  
the sliders 7being in iron7 at pleasure4
   ,the barrel of the lock in which the 
sliders act1 instead of being   whole   
length from front to back of padlock1   
was not quite half its   proper length2 
a serious oversight in the workman who  
put the lock   together1 as the barrel  
being short1 the sliders were           
necessarily so1   which diminished the  
number of notches in the sliders full   
one-half1   and to that extent          
diminished the security of the lock1 and
 increased   the facility of the        
operator4    8,we send for your         
inspection a box of guards1 which will  
shew you the   barrel and sliders of our
 ,bramah lock4 ,you will observe several
   notches in each slider1 only one of  

which will turn on the   locking-plate1 
the others being what are termed false1 
or security   ones4 ,these notches being
 cut only the exact width of the        
locking-plate1 require the most perfect 
accuracy to carry each down to   its    
proper distance4 ,in the lock on which  
,mr4 ,hobbs operated1 in   addition to  
the sliders being so short1 and only    
half the number of   security-notches in
 each1 the notch which passed round the 
locking-plate was found to be cut twice 
the width it ought to have   been4 ,the 
whole of these defects have been        
corrected since the   ,exhibition4      
8,we are1 ,sir1 yours respectfully1     
8,,bramah and ,co4    8per ,j4 ,,smyth4 
8,to ,john ,weale1 ,esq41 #ei ,high     
,holborn40  ,in the ,jury ,report of the
 ,great ,exhibition1 ,class ,,xxii41 are
 the following remarks3 8,on the        
comparative security afforded by the    
various locks which have come before the
 jury1 they are not prepared to offer an
 opinion4 ,they would merely express a  

doubt whether the circumstance that a   
lock has been picked under conditions   
which ordinarily could scarcely ever1 if
 at all be obtained1 can be assumed as a
 test of its insecurity40 page #ejj4    
,the conditions here alluded to probably
 refer to the free access which ,messrs4
 ,bramah allowed ,mr4 ,hobbs to have to 
their lock during a period of thirty    
days1 and we are hence led to infer that
 the burglar is denied any such         
facilities4 ,on this point we would     
refer to the opinion of a high          
authority4 ,in a paper 8on the ,history 
and ,construction of ,latches and       
,locks10 by ,mr4 ,chubb1 read before the
 ,society of ,arts1 #bb;d ,january1     
#ahea1 the following graphic passage    
occurs3  8,in order to shew the absolute
 necessity of secure locks and safe     
depositories for property1 especially in
 banking establishments1 it may not be  
out of place to trace the systematic    
care and great sagacity with which the  
large burglaries are planned4 ,you will 

bear in mind that an unsuccessful       
attempt is seldom made where the booty  
is of any magnitude4 ,the first-rate    
#8cracksmen' always know beforehand     
where to go1 when to go1 and what they  
are going for4 ,when a #8plant1' as it  
is termed1 is made upon a house or a    
bank1 precise information is gained1 if 
possible1 as to the depository of the   
valuables2 and if it is found that the  
safeguards are too strong in themselves1
 and that the locks are invulnerable1   
the affair is quietly dropped4 ,but if  
otherwise1 then no expenditure of time  
or misapplied ingenuity is spared to    
gain the desired end4 ,the house is     
constantly watched1 the habits of its   
inmates are observed1 their ordinary    
times of going out and coming in are    
noted2 the confidential servants are    
bribed or cajoled1 and induced to leave 
the premises when their employers are   
absent1 so that impressions may be taken
 from the locks1 and false keys made4   
,when all the keys required are made1   

one or two men who have not been        
previously initiated are generally      
called in1 and receive their            
instructions to be ready at a certain   
hour on the following day to enter the  
house4 ,a plan of the premises is put   
into their hands1 they are cautioned to 
step over a certain creaking stair or   
plank1 and the keys of the different    
doors are given them4 ,the day or       
evening is chosen when it is known that 
the inmates will be from home--the      
servant1 taking advantage of their      
absence1 fulfils a long-standing        
engagement with his new and liberal     
friends--a signal is given--the two     
confederates enter--the so-called safe  
is swept of its contents1 all the doors 
are carefully re-locked1 and not until  
the bank is opened for business next    
morning is the robbery discovered40  ,in
 an article in ,frazer's ,magazine for  
,november #aheb the following           
observations were made on the           
,exhibition ,jury ,report on ,locks3    

8,this jury seems to have consisted of  
the only persons in ,england who did not
 hear of the famous #8lock controversy' 
of last year2 for one can hardly imagine
 that1 if they had heard of a matter of 
so much consequence to the subject they 
were appointed to investigate1 they     
would have altogether abstained from    
saying any thing about it4 ,they may be 
excused for not knowing1 because very   
few people did know1 fortunately for our
 safes and strong boxes1 that the mode  
of picking ,bramah's and ,chubb's locks1
 by which the transatlantic ,hobbs      
gained so much glory1 was suggested and 
explained in the ,encyclopdia           
,britannica nearly twenty years ago4    
,but it does seem very strange that     
they1 or at least their reporter1 should
 not have known1 long before the ,report
 finally left his hands1 that ,hobbs had
 picked both of those locks1 and taught 
every lock-picker in ,england how to do 
it1 if he possesses the requisite tools 
and fingers4 ,of course1 however1 the   

reporter did not know it1 as nobody     
could read any newspaper last autumn    
without knowing it4 ,and this jury did  
exercise their judgment to the extent of
 declaring that ,hobbs's own lock 7under
 the name of ,day and ,newell7 #8seems  
to be impregnable4' ,notwithstanding all
 which1 they express their inability to 
#8offer any opinion on the comparative  
security afforded by the various locks  
that have come before them4' ,the only  
discrimination which they venture to    
make is1 that the keys of ,bramah's and 
,chubb's locks are of convenient size1  
while ,hobbs's is ponderous and bulky1  
and his lock complicated2 and they might
 have added 7without any very painful   
amount of investigation71 enormously    
expensive1 in consequence of its        
complication1 and probably also more    
likely1 on the same account1 to get out 
of order and stick fast1 and so become  
rather inconveniently impregnable--on   
the money door of a bank1 for           
instance1--than the other two locks1    

especially ,bramah's40  ,in relation to 
the opinion just given1 it may be       
remarked that the ,american lock has    
shewn no tendencies to get out of order2
 if well constructed 7and good          
construction is a sine qua non in such  
mechanism71 the parts work into and upon
 each other with very little friction4  
,in respect to expense1 and to the size 
of the key1 a bank-lock is not one in   
which economy would be much studied1    
security being the great desideratum4   
,no attempt is made to produce a        
parautoptic lock of small size or for   
cheap purposes4 ,the lock1 therefore1   
must be judged of with reference to what
 it undertakes to perform4 ,and this    
brings us to notice the attempts made in
 ,england to pick the parautoptic or    
,american bank-lock4  ,the following    
were the circumstances connected with   
,mr4 ,garbutt's attempt to pick the     
,american lock4 ,it is of course known  
that a challenge was affixed to the     
,american lock in the ,great            

,exhibition1 and it was this challenge  
which ,mr4 ,garbutt accepted4 ,mr4      
,garbutt1 it may be here observed1 was a
 working locksmith and engineer2 he had 
been entrusted by ,messrs4 ,fox and     
,henderson with the care and adjustment 
of the metal check-tables at the        
pay-places of the ,crystal ,palace2 he  
had at a previous period been in the    
employ of ,messrs4 ,bramah4 ,we mention 
these facts only on account of an       
erroneous rumour at the time that he was
 an agent of ,messrs4 ,bramah in respect
 to the acceptance of the ,american     
challenge2 whereas we believe he acted  
independently1 by and for himself4  ,on 
,sept4 #ajth1 #ahea1 ,mr4 ,a4 ,h4       
,renton1 ,mr4 ,e4 ,h4 ,thomson1 and ,mr4
 ,w4 ,f4 ,shattuck1--the first an       
engineer1 and the other two ,american   
exhibitors1--were appointed arbitrators 
to superintend the arrangements1 and    
they met ,mr4 ,garbutt and ,mr4 ,hobbs  
at the house ,no4 #bj ,knightsbridge4   
,the following conditions were agreed   

to3--,that a ,newell lock should be     
selected1 and should be screwed to a    
wooden box2 that ,mr4 ,garbutt should   
have access only to the key-hole of the 
lock1 through which key-hole all his    
operations for picking the lock should  
be conducted2 that ,mr4 ,garbutt should 
have uninterrupted and exclusive access 
to the box1 between the hours of nine in
 the morning and nine in the evening1   
for thirty days1 beginning on the #aath 
of ,september1 he having during that    
time the privilege of introducing one   
associate1 and the arbitrators reserving
 to themselves the right of inspecting  
the seals placed by them on the box2    
that1 in order to afford every          
information concerning the internal     
arrangement of the lock1 the trial-lock 
should be taken to pieces in presence of
 all the parties2 that it should be     
examined by ,mr4 ,garbutt2 that it      
should be locked and unlocked with the  
proper key by him and by ,mr4 ,hobbs2   
that it should be fastened to a box1 and

 the fastenings sealed by the           
arbitrators2 that the key1 when the lock
 was finally locked1 should be sealed up
 by the arbitrators and delivered to    
,mr4 ,hobbs1 who would retain it until  
required by the arbitrators to hand it  
over to them4 ,that at the expiration of
 the thirty days1 or earlier in case    
either of the success or the abandonment
 of the attempt1 the arbitrators should 
examine the lock4 ,and1 finally1 that if
 ,mr4 ,garbutt should have succeeded in 
picking the lock 7that is1 in           
withdrawing the bolt without injuring   
the lock71 the sum of #bjjl4 should be  
paid to him by ,mr4 ,hobbs4  ,in        
accordance with the above agreement1    
,mr4 ,hobbs produced a parautoptic lock1
 with ten tumblers1 marked ,no4 #hefj4  
,the key and the lock were examined by  
,mr4 ,garbutt4 ,the lock was again put  
together1 affixed to a box1 and sealed4 
,mr4 ,hobbs set the bits of the key 7ten
 in number7 to an arrangement chosen by 
himself1 and the lock was then locked by

 all parties in succession2 the key1    
after the final locking1 being sealed up
 and returned to ,mr4 ,hobbs4 ,mr4      
,hobbs at the same time delivered to    
,mr4 ,garbutt a similar but smaller     
lock1 which he was to be allowed to     
retain during the whole period of the   
trial1 to assist in rendering him       
familiar with the construction of both  
locks4  ,on the #aath of ,october1 the  
day on which the prescribed period      
expired1 the arbitrators met at the     
house in question1 when ,mr4 ,garbutt   
delivered up to them the lock uninjured1
 but unopened4 ,the award of the        
arbitrators was thereupon given in the  
following terms3 8,we therefore hereby  
certify that ,mr4 ,garbutt having had   
uninterrupted and exclusive access to   
the lock during the period of thirty    
days1 and1 availing himself of the      
conditions of the agreement1 had every  
facility for opening the lock that could
 be obtained without possession of the  
true key1 has delivered up the same into

 our hands unopened and uninjured2 and  
the said lock has been delivered by us  
to ,mr4 ,hobbs40  ,it will of course be 
understood that it was one condition of 
this enterprise1 that the particular    
combination of bits in the key wherewith
 the lock was finally locked should not 
be seen by ,mr4 ,garbutt4 ,the key was  
in the first instance tried by ,mr4     
,garbutt and by the members of the      
committee1 and was found to turn readily
 in the lock2 ,mr4 ,hobbs then left the 
room1 and re-arranged the bits of the   
key so as to produce a new combination2 
he then returned to the room1 and locked
 the lock with the key in its altered   
form2 he allowed all present to feel the
 key turn freely1 and then1 without     
allowing any one to see the combination1
 wrapped the key up in paper1 in which  
it was sealed as above described4       
,whether ,mr4 ,garbutt1 or any one1     
could have succeeded better by a        
momentary glance at the arrangement of  
the key1 was not at that moment the     

question3 the terms of the challenge    
were that he should not see it4 ,what   
are the circumstances likely to occur if
 the operator really has access to the  
key 7provided the bits are not very     
numerous7 we may shortly explain4  ,it  
is necessary to draw a distinction      
between picking of a lock and ringing   
the changes on a permutating key2       
otherwise some of the late occurrences  
connected with locks can hardly be      
understood4 ,after the reading of a     
paper by ,mr4 ,hobbs before the ,society
 of ,arts1 a discussion arose1 in which 
it was stated that the ,newell lock had 
been picked in ,london4 ,mr4 ,hobbs     
deemed it necessary to refute this      
statement4 ,the report was circulated in
 many of the ,london newspapers2 and    
,mr4 ,jeremiah ,smith1 the operator in  
question1 supported it by his own       
statement4 ,under these circumstances   
,mr4 ,hobbs1 on ,april #b1 #aheb1       
addressed a letter to the editor of the 
,observer2 of which the following       

paragraph was intended to point out the 
distinction above mentioned between     
8picking0 and 8ringing the changes30    
8,early last autumn ,i lent to ,mr4     
,potter1 of ,south ,molton ,street1 one 
of my locks1 for the purpose of giving  
him an opportunity to make himself      
acquainted with its principle and       
construction4 ,after he had had the lock
 in his possession several weeks1 a     
report reached me that one of ,mr4      
,potter's workmen had picked my lock4 ,i
 immediately called on ,mr4 ,potter to  
ascertain the fact4 ,mr4 ,potter        
informed me that for the purpose of     
testing the possibility of opening the  
lock by means of an impression taken1 or
 a copy being made of the true key1 ,mr4
 ,smith had made a copy of the key by   
means of a transfer instrument1 which   
instrument he shewed me at the time4    
,after the key was made1 it was tried1  
and found to lock and unlock the lock as
 readily as the original key4 ,mr4      
,potter then sealed the screws of the   

lock1 changed the combination of the    
key1 and locked it4 ,mr4 ,smith then    
took the lock1 and with the key that he 
had made by copying the original1 hit   
the combination1 and unlocked it4 ,the  
lock was of the smallest size1 having   
but six tumblers2 the number of changes 
that could possibly be made were #gbj4  
,the time occupied by ,mr4 ,smith1      
according to his own statement1 was six 
hours and fifty-five minutes2 this1     
allowing one minute for each change1    
would give him time to have made #dae   
out of the #gbj changes before hitting  
the right one4 ,i asked ,mr4 ,smith why 
he did not use the original key instead 
of making a copy8 ,his answer was1 that 
#8he could change the one he made       
faster1 as he did not have to screw the 
bits in4' ,any person will readily      
understand the difference between       
ringing the combination of a key and    
picking a lock40  ,in other words1 the  
process was this3 the operator had the  
true key1 and might have used either    

this or one which he made from it4 ,this
 would have sufficed for opening almost 
any lock ever constructed instantly2 but
 in the ,american lock he had to find   
out which of #gbj combinations was the  
right one1 and he was employed almost   
seven hours in doing this4 ,the exploit 
shewed patience1 but had little bearing 
on the practical subject of             
lock-picking4  ,in ,march #aheb ,mr4    
,smith put forth an offer to accept the 
challenge made by ,mr4 ,hobbs in respect
 to the ,exhibition lock4 ,mr4 ,hobbs   
agreed to the offer1 and chose1 as      
arbitrators on his part1 ,mr4 ,hensman1 
,engineer to the ,bank of ,england1 and 
,mr4 ,appold1 inventor of the           
centrifugal pump which attracted so much
 attention at the ,great ,exhibition4   
,mr4 ,hobbs requested ,mr4 ,smith to    
appoint arbitrators on his side also2   
but this was not done4 ,mr4 ,smith1 at a
 meeting held by the four persons named1
 expressed a wish that an ordinary      
commercial lock should be the one       

experimented on1 instead of the more    
complicated test-lock which had been at 
the ,great ,exhibition4 ,this was a     
departure from the terms of the original
 challenge2 but ,mr4 ,hobbs waived his  
objection on this point1 and offered to 
substitute a bank-lock with ten tumblers
 for the ,exhibition lock with fifteen1 
the former being similar in construction
 but less complex4 ,another meeting was 
agreed upon1 but ,mr4 ,smith did not    
attend2 and the matter was1 by himself1 
brought to a sudden termination4  ,to   
shew the effect of difference in the    
number of tumblers and key-bits1 we may 
state that1 while1 at a minute per      
change1 it would take twelve hours to go
 through all the combinations with a    
six-bitted key1 it would require seven  
years with a ten-bitted1 and #b1ejj1jjj 
years with a fifteen-bitted key6 ,so    
much for power of combination1 in the   
arithmetical mode of picking4  ,we now  
proceed to notice the violability of    
sundry minor locks4 ,it might at first  

appear that the letter-lock is          
exceedingly difficult to pick2 and so it
 unquestionably is1 as long as we merely
 attend to the chance-medley trials by  
turning the rings round and round until 
we happen to hit upon the right         
combination4 ,but there is another mode 
of solving the riddle1 mechanical rather
 than arithmetical4 ,a piece of common  
wire1 bent in the form of the shackle1  
is put in between the ends of the lock2 
the spring or elasticity of the wire    
tends to force the ends apart2 this     
causes the pins or studs on the rod to  
press against the inner edges of the    
rings4 ,by trying all the rings in      
succession1 some one of them will be    
found to bind or cling more than the    
others2 this is turned round until the  
cessation of the bind shews that the    
notch in the ring has been brought into 
its right position relatively to the pin
 on the rod4 ,then another ring which   
binds more than the rest is treated in a
 similar way2 until at length all the   

rings seem to be so far liberated as to 
indicate that the notches are in the    
right positions4 ,in the dial-lock1     
similarly1 when a pressure has been     
brought to bear upon the bolt in the    
right direction1 a trial of the pointers
 will soon bring the notch in each wheel
 to the required position4  ,some short 
time after the events in ,london        
connected with the lock controversy1    
,mr4 ,william ,brown of ,liverpool      
described the letter-lock noticed in a  
former page1 characterising it as a lock
 which he believed no one could pick4   
,an incident in the history of this lock
 was thus narrated in one of the        
,liverpool newspapers4 8,mr4 ,hobbs was 
taken by ,mr4 ,milner to the office of  
,messrs4 ,brown1 ,shipley1 and ,co41 and
 shewn this lock4 ,the safe-door was    
closed and locked by the cashier at ,mr4
 ,brown's request2 and then ,mr4 ,hobbs 
began to illustrate his views of the    
construction of the lock by manipulation
 and explanation1 with which the subject

 of them appeared to sympathise so      
entirely and promptly that the door     
opened in a few minutes40  ,in respect  
to the picking of the ,egyptian lock1   
the main difficulty would be in         
obtaining any false key that would      
correspond with the pins of the lock2   
but this might be accomplished in a way 
analogous to that which is practised in 
many other cases4 ,if a small piece of  
wax be laid on a blank key1 the key     
inserted into the lock1 and the blank   
pressed upwards against the pin-holes1  
there would be left an impression of    
those holes on the wax2 this impression 
would furnish a guide to the fabrication
 of a false key4 ,there is also very    
little difficulty in picking this lock  
by one of the ordinary instruments4     
,for the ,yale lock1 combining something
 like the pin-action of the ,egyptian   
with the cylinder-action of the ,bramah 
locks1 the picking requires the use of  
an instrument that will fit between two 
of the pins1 and to the outer end of    

which is attached a lever and weight2 by
 this means a pressure is exerted upon  
the cylinder in the right direction for 
it to turn1 and the pins are made to    
bind4 ,then1 with another instrument1   
the pins are felt1 and each one moved   
until it seems to be relieved from the  
bind3 this indicates that the joint in  
the pin coincides with the joint between
 the two cylinders2 and when all have   
been similarly treated1 the weight      
acting on the inner cylinder will turn  
it4 ,it is evident that this method is  
the same in principle as the one        
applicable to the ,bramah lock4         
,,chapter ,x4  ,,effects ,,of ,,the     
,,great ,,exhibition ,,of #ahea ,,in    
,,improving ,,english ,,locks4   ,we    
have now to refer to the effects of the 
lock controversy4 ,it was no doubt      
annoying to be told1 on good authority1 
that the machines on which we so much   
prided ourselves were wrong in          
principle2 and that our locks1 in order 
to afford the degree of security which  

are expected of such contrivances1 must 
be re-constructed4 ,the grumbling with  
which the first part of this proposition
 was received would alone have sufficed 
to lead to a suspicion of its truth1 if 
the large number of new locks that have 
actually appeared had not confirmed it4 
,whether the second part of the         
proposition has been fairly carried out1
 is a point which must now be           
considered4  ,one of the first locks    
produced during or immediately after the
 lock controversy was ,mr4 ,parnell's1  
to which the bold term of patent        
defiance lock is attached4 ,this lock is
 said to depend for its security on a   
mode of arrangement which may best be   
described in the inventor's own words3  
8,viewing the lock from its exterior1 it
 presents nothing remarkable2 but1 upon 
removing the plate1 it will be seen that
 all possible access to the mechanism   
with false or surreptitious keys is     
effectually prevented by a solid        
cylinder of hardened 8 brass1 with      

protecting wards extending the whole    
depth of the lock1 and having in the    
centre the aperture for the key1 which  
fits to a mathematical nicety so exact  
as to preclude the possibility of any   
second instrument being used to open    
it4444 ,this protecting cylinder must   
revolve with the key to get to the      
works2 and the moment it passes from the
 key-hole in going round to lock or     
unlock1 the solid portion moves into its
 place1 and so completely closes that   
aperture that the point of a pin1 or a  
fine steel-pen1 has failed to be        
inserted between it and the outer plate 
or cap1 to say nothing of the utter     
hopelessness of perforating the metal4  
8,the cylinder or protecting cap1 though
 it revolves by the action of the key   
somewhat in the same way as the cylinder
 of the ,bramah lock1 appears to be     
intended rather for closing or          
protecting the key-hole than for        
governing the movements of the bolt4    
,the internal arrangements of the lock  

are as follow3 ,supposing the bolt to be
 shot1 and to be about to be unlocked1  
the key1 by the time it has made about  
one-third of a rotation1 meets with a   
forcible resistance in the shape of an  
upright spring-bolt or detector of      
strong steel acting on the revolving    
cylinder4 ,the key passes this detector1
 and arrives at the levers or tumblers4 
,in the bolt-stud which works in the    
slot of these tumblers there is a small 
deep serrated notch on one side1        
corresponding to similar notches on each
 of the tumblers2 if1 therefore1 the    
bolt be forced1 these notches would lock
 into each other in a similar manner to 
the catch on a ship's windlass or a     
hoisting crane4 ,there is also a        
double-action tumbler-bolt1 so adjusted1
 that if any of the tumblers be         
overlifted1 this little appendage       
becomes thrust down at one end into the 
bolt of the lock1 where it wedges all   
fast until the tumblers become properly 
re-adjusted4 ,the double-action         

tumbler-bolt also falls into the        
lock-bolt when the latter is locked or  
shut1 thereby imparting an additional   
strength to the lock4 ,the key has a    
power of expansion or enlargement while 
turning in the lock2 it meets with an   
eccentric plate which draws out the bits
 somewhat2 so that1 at the moment of    
acting on the tumblers1 they protrude   
farther from the pipe of the key than   
when the key entered the key-hole4 ,the 
key is1 in fact1 larger when in than    
when out of the lock4 ,there is         
connected with the works of the lock a  
#8detention-cap1' so formed that1 in the
 event of a false key being used1 a     
powerful bolt instantly locks into the  
revolving cylinder1 and holds fast the  
surreptitious instrument40 ,such is1 in 
substance1 the account which ,mr4       
,parnell has given of his own lock4 ,it 
must1 however1 be stated1 that the      
points of security or novelty claimed by
 ,mr4 ,parnell for his lock were        
patented by previous inventors4 ,the    

revolving cylinder or curtain was       
claimed by ,mitchell and ,lawton in the 
patent of #gth ,march1 #ahae1 as noticed
 at page #eb ante4 ,the expanding       
key-bit was claimed by ,mr4 ,machin of  
,wolverhampton in #ahbg1 as noticed at  
page #fa1 and by ,mr4 ,mackinnon 7page  
#fb72 while the serrated notches in the 
tumbler were used by many lock-makers   
long before the date of ,mr4 ,parnell's 
patent4 ,the detention-cap for catching 
and holding a false key when put into   
the lock was also patented by ,mitchell 
and ,lawton1 as noticed at page #ec     
ante4  ,we come now to notice a lock    
lately invented by ,mr4 ,e4 ,b4 ,denison
 7the author of the ,rudimentary        
,treatise on ,clocks in this series71   
which has the merit of combining        
considerable novelty in construction    
with security4 ,after the details given 
in the two preceding chapters1 it will  
certainly be no small praise when we    
express our conviction that in the      
present state of the art of             

lock-picking1 this lock may be          
considered as secure4 ,mr4 ,denison has 
furnished us with a description of his  
lock1 which we insert almost in his own 
words4 ,mr4 ,denison claims for this    
lock the following advantages3--  #a4   
,that a very large and strong lock on   
this construction only requires a very  
small key4 #b4 ,that no key is required 
to lock it1 although it is free from the
 inconvenience pertaining to            
spring-locks1 viz4 that the door cannot 
be shut without locking itself4         
,moreover this lock is more secure than 
any spring-lock can be4 #c4 ,that it    
cannot get out of order from the usual  
causes of the tumblers sticking together
 or their springs breaking1 inasmuch as 
the action of the tumblers does not     
depend on any thing but the key and the 
handle1 and there are no                
tumbler-springs4 #d4 ,that for the same 
reason1 the parts of this lock do not   
require any polishing or delicacy of    
execution4 #e4 ,that the key-hole being 

completely closed by a curtain1 except  
when the key is in1 the lock is         
protected from the effects of the       
atmosphere and dust entering at the     
key-hole4 #f4 ,that this lock is secure 
against any known mode of picking2 the  
smallness of the key-hole prevents the  
insertion of any instrument strong      
enough to open the lock by violence4 #g4
 ,that this lock1 from the simplicity of
 its construction1 admits of being made 
at small cost4  ,these objects are      
accomplished as follows3--,in the       
large-sized locks1 such as would be used
 for safes and large doors1 the tumblers
 ,t1 fig4 #ea1 are made of pieces of    
hoop-iron1 #f or #g inches long and #a  
inch wide3 these tumblers are supported 
by and turn on a pin a1 placed at about 
the middle of their length2 so that     
being balanced on the pin1 or nearly so1
 and having their separating plates ,p  
between them1 which cannot turn1 the    
tumblers will stand in any position     
indifferently2 and in order to secure   

sufficient friction to keep them steady1
 one or more of the separating plates ,p
 is bent a little1 so as to act as a    
spring when the cap of the lock is      
screwed down4 ,the lock is shewn in fig4
 #ea as locked1 the bolt ,b having been 
shot by the fantailed piece f on the    
handle1 and the tumblers sent down1 so  
that the stump s cannot enter their jaws
 by the other piece of the handle2 and  
it is evident that the handle cannot    
draw the bolt back again until the      
tumblers have all been raised by the key
 to the proper position to allow the    
stump s to enter their jaws4 ,it will be
 observed that in the position shewn in 
the figure1 the stump does not touch the
 tumblers2 and consequently1 so long as 
the bolt is kept in the position        
represented1 no pressure of the stump   
against the tumblers can be felt1       
although by means of a false key or     
pick-lock the tumblers be raised to any 
height4 ,no implement1 however1 can be  
pushed into the key-hole without first  

pressing in the curtain ,k1 which is    
held up against the cap of the lock by  
the two spiral springs c c on each side 
of the key-hole2 and at the back of the 
curtain there is a square plug p1 which 
goes through a hole in the back of the  
lock1 and has a notch in it through     
which the bolt can pass when the curtain
 is up1 closing the key-hole1 but at no 
other time4 ,in other words1 the act of 
pushing in the key sends down the       
curtain plug1 the effect of which is to 
hold the bolt fast in the position in   
which the stump cannot be made to touch 
the tumblers4 ,if the proper key be used
 and turned about half round to the     
right1 it will bring the tumblers to the
 proper height for the stump to pass4   
,the key is then taken out2 for so long 
as it is in the lock1 the bolt cannot be
 moved2 and then turning the handle to  
the right1 the bolt is drawn and the    
door opened4  ,illustration3 fig4 #ea4  
,mr4 ,denison's large lock4  ,the handle
 ,h should be so made1 that as soon as  

the fantailed piece f has sent the bolt 
just clear of the tumblers1 the other   
arm to the right of ,h may begin to move
 the tumblers2 but the fantail need not 
send the stump above one-sixteenth of an
 inch beyond the tumblers2 and the      
curtain-plug and bolt must be so        
adjusted that the curtain cannot be     
pushed in until the bolt is so far out  
that the stump is this one-sixteenth of 
an inch beyond the tumblers4 ,the       
curtain ,k need only be a thin piece of 
steel1 and the bolt ,b must be thick    
enough for the curtain to go down just  
to the level of the thin plate ,p       
between the bolt and the first tumbler  
,t4 ,the curtain-plug p is made as long 
as the key-hole and rather broader1 and 
of the shape represented1 partly for the
 sake of steadiness in pushing in the   
curtain1 and also for more completely   
protecting the key-hole2 for if an      
attempt be made to pick the lock by     
drilling into the key-hole1 the drill   
will pass into the inside of the door   

and not into the inside of the lock4#aj 
#aj ,mr4 ,denison informs us that there 
is a further contrivance1 which   he    
will explain privately to any persons   
who wish to manufacture these   locks1  
of which the object is1 not to add any  
thing to the security of   the lock     
under ordinary circumstances1 but to    
provide against the   unusual case of a 
very dexterous thief having occasional  
access to the   lock when open2 in which
 case 7but for some such further        
provision7 he   might manage to         
construct a false key capable of opening
 the lock at   any other time1 by a     
method which1 for obvious reasons1 it is
 not   advisable to publish4  ,it is    
true that iron safes have been made for 
some years in which any number of large 
bolts are shot by a handle and then     
locked by a very small key4 ,but in such
 locks the key must be used in locking1 
and this leads to certain objections1   
viz4 the key must occasionally at least 
be confided to some person whose duty it

 is to lock up the safe after the owner 
has left the place2 there is also the   
temptation to leave the key in the lock1
 since it will be wanted in locking up2 
and thus there is the danger of some    
dishonest person taking an impression of
 the key4 ,besides this1 the real       
strength and security of such safes is  
only that due to the small lock which   
locks into the main bolt2 whereas in    
,mr4 ,denison's lock the security and   
strength are those due to the lock      
itself1 with its large and strong       
tumblers1 and other provisions peculiar 
to its construction2 and the key for a  
lock of the largest size1 which was     
lately exhibited at the ,society of     
,arts by ,messrs4 ,s4 ,mordan and ,co41 
the makers1 only weighs a little more   
than a quarter of an ounce4 ,it may be  
mentioned that for large locks the key  
may be solid1 although in the small ones
 it is more convenient to have a        
pipe-key1 on account of the different   
construction of the curtain4            

,illustration3 fig4 #eb4 ,mr4 ,denison's
 small lock4  ,the arrangement of the   
small lock for drawers1 c4 is somewhat  
different from that of the large ones1  
and will be understood by referring to  
fig4 #eb4 ,the action of the handle ,h  
on the bolt ,b and on the tumblers ,t is
 sufficiently clear from the figure4    
,the curtain in this case has no plug1  
but is only a flat plate held up by a   
thin spring behind it1 and moving up and
 down on the drill-pin of the key1 and  
kept from turning by having one edge    
against the side of the lock4 ,the bolt 
has a kind of second stump1 only coming 
up so high as to be able just to pass   
under the corner of the curtain when it 
is up1 but not able to pass when the    
curtain is at all pressed down by any   
thing inserted in the key-hole4 ,in a   
drawer lock the key has only to be      
turned a quarter round in order to raise
 the tumblers4 ,in small locks1 the     
friction of the tumbler-plates is quite 
enough to keep them in any position1    

without putting the pin in the middle so
 as to balance them1 as in large locks  
with heavy tumblers4  ,in the making of 
these locks the key must be made first1 
with proper provisions to prevent the   
repetition of the same pattern2 a kind  
of pattern or model for locks of each   
size should be made2 the tumblers put on
 the pin with plates of the intended    
thickness between1 and when raised by   
the key to the proper height they should
 be clamped down2 and the jaws for the  
stump of the bolt may then be cut by a  
circular saw moving in a slit in the    
model corresponding to the place of the 
stump4 ,the tumblers for large locks may
 be cut off from a strip of hoop-iron to
 the proper lengths by a stamping       
cutter1 giving them the proper circular 
end1 and a punch might at the same time 
make the pin-hole in the middle4 ,the   
tumblers for small locks should be      
stamped out of sheet brass or iron4  ,it
 will thus be evident that from the     
general simplicity of construction1 and 

the small amount of finish required in  
the working parts1 this lock can be made
 at small cost4 ,we may also add that   
this lock is as creditable to the public
 spirit as to the mechanical skill of   
the inventor2 for the lock is not       
patented1 patents being1 in ,mr4        
,denison's estimation1 obstructions to  
the progress of science4  ,the next     
result of the 8lock controversy0 which  
we have to notice is the production of  
not less than three improved locks by   
,messrs4 ,chubb4 ,we thought it our duty
 to invite the attention of this        
celebrated firm to the preparation of   
this ,rudimentary ,treatise1 and in     
answer to the application of our        
publisher we received the following     
communication from ,messrs4 ,chubb1     
which we insert verbatim3--  8,it will  
not be necessary to describe the lock as
 originally made1 as a description of it
 will be found in ,mr4 ,chubb's paper   
read before the ,institution of ,civil  
,engineers4  8,,lock ,,no4 #a4--,the    

first of the improvements introduced    
consists of a barrel1 to which a        
circular curtain is attached1 revolving 
round the drill-pin in the lock2 so that
 if any instrument is introduced to     
attempt to pick it1 the curtain         
immediately closes up the key-hole1 and 
prevents the introduction of any        
auxiliary instruments1 there being      
several required in action at once to   
produce any effect4  8,if by any means  
these several instruments can be        
introduced simultaneously1 the barrel   
keeps them all confined in a very small 
space1 preventing their expansion1 and  
renders it impossible to work them      
independently of each other2 therefore  
they are of no avail1 being incapable of
 acting as more than a single pick1     
which is perfectly useless4 ,the barrel 
and curtain have each been previously   
used separately in locks1 but until     
patented by ,mr4 ,de la ,fons in #ahdf  
they had not been used in combination4  
,neither of them1 used separately1 is of

 much use1 but when combined they afford
 a very great security4 ,locks have     
been1 and still are shewn1 containing   
either the barrel or curtain singly1 and
 as these have been picked1 it has been 
asserted that the improvement now       
introduced in ,chubb's lock is equally  
insecure2 but a slight examination of   
the difference in their construction    
will prove the contrary4 ,mr4 ,chubb has
 purchased the patent-right of this part
 of ,mr4 ,de la ,fons' invention1 and   
applies it to all his locks4  8,,lock   
,,no4 #b4--,the next improvement1       
recently patented by ,mr4 ,chubb1 is    
based upon the assumption that there may
 be a possibility of overcoming the     
security of the barrel and curtain as   
already described 7although this        
assumption is not in the slightest      
degree admitted71 and consists in       
applying what is called a               
#8tumbler-bolt1' working on a hinge     
connected with the main bolt4 ,the web  
of the key does not in any case touch   

the main bolt in unlocking1 but acts    
only on the tumbler-bolt4 ,all the      
tumblers must first be lifted1 each to  
its proper position1 before the         
tumbler-bolt will act4 ,should any      
pressure be applied to either bolt      
before the tumblers are all at their    
exact position1 the effect would be to  
throw the bolts out of gear1 and thus   
effectually to stop the stump of the    
main bolt from passing through the racks
 of the tumblers4 ,none of the many     
plans of picking which have been        
suggested1 such as smoked key-blanks1   
thin key-bits1 c41 would be of the least
 avail against a lock made on this      
principle4 ,different kinds of detectors
 may be applied to these locks4 ,it is  
submitted that this lock1 retaining all 
the simplicity and durability which have
 distinguished ,chubb's lock for so many
 years1 and combining with them these   
important improvements1 affords a       
complete security against all           
surreptitious attempts of any nature4   

,locks on the same principle are being  
made on the permutation plan1 with any  
number of tumblers1 and any number of   
changes in combination that may be      
desired4  8,it has been suggested that  
the #8detector1' instead of giving      
additional security to ,chubb's lock1   
affords a partial guidance to a person  
attempting to pick it4 ,this objection  
holds good to a certain extent in these 
locks as originally made1 in which all  
the tumblers had an equal bearing       
against the detector-stump2 but in the  
locks as now constructed this objection 
is entirely obviated1 by giving the     
tumblers an unequal bearing1 whereby1 if
 an operator feels the obstruction of   
the detector-stump1 he cannot tell      
whether the tumbler which he is lifting 
is raised too high1 or not high enough4 
8,,lock ,,no4 #c4--;,for banks1 ,mr4    
,chubb has introduced what he           
particularly calls his #8bank lock4' ,it
 contains a barrel with a series of     
curtains4 ,while the key-hole is open1  

all access to the tumblers from the     
key-hole is completely cut off by two   
sliding pieces of solid metal1 which fit
 closely on either side of the barrel4  
,these pieces are acted upon by an      
eccentric motion1 so that when the key  
is applied to the lock1 and turned in   
it1 the key-hole is shut up by the      
revolution of the curtains1 and then    
only do the sliding pieces of metal move
 aside to allow the key to act upon the 
tumblers4 ,these pieces return to their 
position when the key has passed2       
therefore1 while the key is lifting the 
tumblers1 all communication is cut off  
from the exterior of the lock by these  
sliding pieces and the series of        
curtains4 ,the bolt is made in two      
pieces1 the main bolt never being in    
contact with the key1 which acts only on
 the talon-bolt1 and by it transmits the
 motion to the main bolt4 ,after the    
action of locking1 the talon-bolt is    
partly repelled1 and a lever or #8dog'  
connected with it locks into a series of

 combinations arranged upon the front   
parts of the tumblers1 and holds them   
securely down1 so that none of them can 
be lifted in the least degree until the 
talon-bolt is thrown forward to release 
them1 ,if1 therefore1 any pressure be   
applied to this talon-bolt1 to endeavour
 by its help to ascertain the           
combinations of the tumblers1 it will   
only the more tightly lock them down1   
and render the attempt ineffectual4 ,by 
another contrivance it is rendered      
impracticable to move a pick or picks   
round in the lock more than a small     
distance1 unless the tumblers could     
previously be all lifted to their right 
positions1 which can only be done by the
 right key4 ,should one or more of the  
tumblers be surreptitiously raised by   
any possible means1 they cannot be      
detained in this uplifted position1 for 
the action of turning back the pick to  
try to raise another tumbler sets in    
motion a lever which allows the tumblers
 already raised to drop to their former 

position1 leaving the operator just as  
far from the attainment of his object as
 at the outset40  ,such is the statement
 with which ,messrs4 ,chubb have        
favoured us respecting their three new  
locks4 ,we are willing to admit the     
enterprising spirit which has led to    
their production1 and the ingenuity     
which has been bestowed on their        
construction2 but whether they mark a   
step in advance in the art of           
lock-making may perhaps admit of doubt4 
,with respect to the lock ,no4 #a1 we   
would remark1 that locks with the barrel
 and curtain combined were made by ,mr4 
,aubin of ,wolverhampton in #ahcc1 and  
that a specimen of such a lock was      
exhibited on his stand of locks in the  
,great ,exhibition4 ,locks with the     
combined barrel and curtain were also   
made and sold by ,mr4 ,jones of ,newark1
 ,n4,j41 as stated at p4 #ajd4  ,with   
respect to the lock ,no4 #b1 the object 
of the tumbler-bolt is evidently        
intended to produce the same effect as  

the movable stump in ,mr4 ,hobbs's      
protector-lock1 fig4 #dg1 page #ajj2 but
 with greater complexity in the         
construction1 there is less efficiency  
in the action of this part of ,mr4      
,chubb's lock as compared with that of  
,mr4 ,hobbs1 inasmuch as a pressure of  
the stump against the tumblers1         
corresponding with the strength of the  
spring which holds the bolt in its      
place1 can always be produced1 thereby  
giving friction1 and affording          
indication as to which tumbler it is    
that is in tight contact with the stump4
  ,with respect to the barrel and       
curtains of lock ,no4 #c1 and all       
similar contrivances1 the object of     
which is said to be to prevent the      
entrance into the key-hole of all       
instruments except the proper key1 we   
would offer the self-evident remark1    
that the same aperture which admits the 
key will also admit some other          
instrument4 ,in the case of ,mr4        
,chubb's 8bank-lock10 it may be         

questioned whether the revolving        
curtain1 c4 give it any advantage over  
the other locks already referred to     
which are furnished with similar        
contrivances4 ,the effect of the        
talon-bolt in this lock appears to be   
the same as that of the false notches1  
namely1 to hold the tumblers in the     
position in which they were placed when 
the pressure was applied4 ,hence1 a     
pressure applied to the talon-bolt      
affects the parts which come in contact 
with the key in the act of locking and  
unlocking2 and this circumstance brings 
the lock under the application of the   
principle stated at page #ii1 and thus1 
if this principle be admitted1 may      
render the security of the lock somewhat
 questionable4  ,various other locks    
have been brought out since the date of 
the 8lock controversy0 in the year      
#ahea4 ,we would gladly notice them all1
 did they shew novelty of design and    
mark an advance in the art of the       
locksmith4 ,we must1 however1 admire the

 ingenuity with which ,mr4 ,hobbs's     
movable stump has been more or less     
adopted2 but in the attempts to imitate 
it the objection has not been removed1  
that it is possible to produce on the   
tumblers a pressure or friction equal to
 the strength of the spring which holds 
the tumblers down4  ,there is1 however1 
a lock which has lately been introduced 
to the public1 which calls for special  
notice1 on account of the high honours  
which have been bestowed upon it4 ,we   
refer to the prize lock of the ,society 
of ,arts1 ,london1 the invention of ,mr4
 ,h4 ,j4 ,saxby of ,sheerness1 who has  
received the ,society's medal and the   
sum of ten guineas as the reward of his 
ingenuity4 ,the interior of this lock   
consists of a cylinder with four pins or
 slides radiating from the centre1 and  
pressed into the key-hole by means of   
spiral springs4 ,the pins project beyond
 the periphery of the wheel or cylinder1
 and into slots in a ring which is      
affixed to the case of the lock1 thereby

 preventing the cylinder from being     
turned4 ,on each pin is a notch1 so     
placed that when the proper key is      
inserted into the key-hole1 the notches 
on the several pins will be brought into
 a position such as will allow the      
cylinder to turn4 ,the turning of the   
cylinder in this1 as in the ,bramah     
lock1 shoots the bolt4  ,a lock on      
precisely the same principle1 but more  
secure in its construction1 was         
described by ,mr4 ,hobbs in a paper read
 by him before the ,society of ,arts in 
,january #aheb1 when diagrams           
illustrative of the same were exhibited4
 ,this paper was not reported at any    
length in the journal of the ,society's 
proceedings2 but the same paper was read
 by ,mr4 ,hobbs1 ,march #a1 #aheb1      
before the ,liverpool ,polytechnic      
,society1 and a full report thereof1 and
 a description of the lock in question1 
is given in the 8,transactions0 of that 
,society1 from ,september #ahdi to      
,december #aheb 7#hvo1 ,liverpool1      

#ahec74 ,this lock is no other than the 
,yale lock already noticed at page #hc1 
and is thus described at page #aif of   
the 8,transactions30  8,another         
description of cylinder-lock was        
invented1 a few years since1 by a ,mr4  
,yale of the ,state of ,new ,york1      
,u4,s4,a4  8,the ,yale lock has two     
cylinders1 one working within the other2
 and they are held together by a series 
of pins reaching through the cylinders  
into the key-hole1 which is in the      
centre4 ,on the back of the inner       
cylinder is a pin that fits into a slot 
in the bolt1 and moves it as the        
cylinder is turned4 ,the pins that hold 
the cylinders together and prevent the  
inner one from turning1 are cut in two  
at different lengths4 ,the key is so    
made1 that by inserting it into the     
key-hole the pins are moved1 so that the
 joint in the pins meets the joint      
between the cylinders1 and allows the   
inner one to be turned4 ,but1 as with   
the slides of the ,bramah lock1 should  

any one of the pins be pushed too far1  
the cylinder is held quite as firmly as 
though it had not been touched4 ,some of
 these locks have been made with as many
 as forty pins2 and to a person         
unacquainted with the principles on     
which locks are picked1 they would seem 
to present an insurmountable barrier4   
8,figure #aaa represents the case of the
 lock containing the bolt ,a1 having a  
groove ,b1 to receive the pin ,c on the 
cylinder4 ,figure #b shews the cap or   
top-plate of the lock1 and the          
cylinders2 ,d ,d is the outer cylinder1 
that is stationary1 being fastened to   
the plate2 ,e ,e the inner or moving    
cylinder2 ,f ,f the four rows of pins1  
being cut in two at different lengths1  
and reaching through the cylinders into 
the key-hole2 ,g ,g are the springs that
 press the pins to their places2 ,c the 
pin that fits into the groove and moves 
the bolt4 ,figure #c is an end view of  
the key1 shewing four grooves4 ,figure  
#d is a side view1 shewing the irregular

 surface of the grooves by which the    
pins are adjusted4    #aa ,this and the 
following figures refer to the diagrams 
exhibited by   ,mr4 ,hobbs4  8,for the  
purpose of picking the lock1 an         
instrument is made that will fit between
 two of the pins2 to that is attached a 
lever and weight1 thereby getting a     
pressure on the cylinder and causing the
 pins to bind2 then with another        
instrument the pins are felt1 and as    
they are found to bind1 they are pressed
 in until they are relieved 7as they    
will be when the joint comes to the     
right place71 thereby easily opening the
 lock4 ,there is a great similarity in  
the operation and security of this and  
the lock manufactured by ,mr4 ,cotterill
 of ,birmingham40  ,in the ,society of  
,arts ,journal for the #bdth ,june1     
#ahec1 is a letter from ,mr4 ,hobbs on  
the subject of the prize lock1 which1 it
 appears1 he picked1 8in the presence of
 parties connected with the ,society1 in
 the short space of three minutes40     

,,chapter ,,xi4  ,,the ,,lock ,,and     
,,key ,,manufacture4   ,the manufacture 
of locks and keys1 considered as a      
department of working in iron1 is one   
that requires1 and indeed admits of1    
very little description4 ,the hammer1   
the file1 the drill1 the fly-press1 are 
the chief instruments employed2 the iron
 itself being brought to something like 
the desired state and form by rolling or
 casting1 or both4 ,but the manufacture 
is interesting in its social            
features--in its relation to the persons
 employed and the buildings occupied4   
,one by one1 several departments of     
industry have progressed from the       
handicraft to the factory system--from  
that system in which a man and a few    
apprentices work in a small shop in the 
lockmaker's garret or kitchen1 to that  
in which organisation is maintained     
among twenty or fifty or a hundred men4 
,locks have scarcely yet passed out of  
the first stage1 but there is no good   
reason whatever why they should so      

remain2 there are as many reasons for   
progress in this as in other arts1 and  
indications are not wanting that some   
such progress will be made4  ,so far as 
,england is concerned1 the neighbourhood
 of ,wolverhampton is the great         
storehouse whence locks are obtained4   
,eminent lock-makers reside in ,london  
and in other principal towns2 but       
,wolverhampton is regarded by all as the
 centre of the trade4 ,this is not a    
modern localisation1 for we have        
information respecting the locks of     
,wolverhampton a century and a quarter  
ago4 ,among the ,harleian ,manuscripts  
is an account of 8,the ,voyage of ,don  
,manuel ,gonzales 7late merchant71 of   
the ,city of ,lisbon in ,portugal1 to   
,great ,britain3 containing an          
,historical1 ,geographical1             
,topographical1 ,political1 and         
,ecclesiastical ,account of ,england and
 ,scotland2 with a ,curious ,collection 
of things particularly rare1 both in    
,nature and ,antiquity40 ,this ,ms4     

appears to have been written about      
#agcb2 it was translated from the       
,portuguese1 and printed in ,pinkerton's
 ,collection of ,voyages and ,travels4  
,with reference to ,wolverhampton1      
,gonzales says3 8,the chief             
manufacturers of this town are          
locksmiths1 who are reckoned the most   
expert of that trade in ,england4 ,they 
are so curious in this art1 that they   
can contrive a lock so that if a servant
 be sent into the closet with the       
master-key1 or their own1 it will shew  
how many times that servant hath gone in
 at any distance of time1 and how many  
times the lock has been shot for a whole
 year2 some of them being made to       
discover five hundred or a thousand     
times4 ,we are informed also that a very
 fine lock was made in this town1 sold  
for #bjl41 which had a set of chimes in 
it that would go at any hour the owner  
should think fit40 ,if ,gonzales were   
correct in these descriptions1 they     
indicate an exercise of considerable    

ingenuity in lock-construction1         
especially in reference to the lock     
which keeps a registry of the number of 
times it has been opened4 ,there is     
abundant evidence that the old          
lock-makers were very fond of these     
knick-knack locks1 which would do all   
sorts of strange and unexpected things2 
and this may in part account for the    
great favour in which locks have been   
held by amateur machinists4  ,the       
lock-manufacture in ,south              
,staffordshire is of a remarkable       
character1 comprised as it is within so 
small an area4 ,although ,wolverhampton 
is known commercially as the chief dept 
of the ,english lock trade1 yet it is at
 ,willenhall1 three or four miles       
eastward of that town1 that the actual  
manufacture is chiefly carried on4 ,when
 the ,commission was appointed a few    
years ago to inquire into the condition 
of children employed in trades and      
manufactures1 ,mr4 ,r4 ,h4 ,horne was   
deputed to examine the ,wolverhampton   

district2 and his report is too curious1
 and too closely connected with our     
present subject1 to be passed unnoticed4
 ,we here give an abstract of such parts
 of his report as bear reference to the 
lock-makers of ,willenhall4  ,almost the
 entire industry of ,willenhall is in   
the three articles of currycombs1 locks 
and keys1 and articles connected        
incidentally with locks1 such as bolts  
and latches4 ,at the time ,mr4 ,horne   
wrote1 in #ahda1 there were among the   
master manufacturers #bfh locksmiths1   
#gf key-makers1 #ad bolt-makers1 and #ac
 latch-makers2 besides many small       
masters living in such out-of-the-way   
corners that they escaped enumeration4  
,in the ,post-,office ,directory of that
 district1 of later date1 there are     
entries of rather a curious character4  
,in the first place it is observable    
that different kinds of locks are made  
by different persons1 each manufacturer 
confining his operations apparently to  
one kind of lock2 one is a rim-lock     

maker1 another a trunk-lock maker1 a    
third a cabinet-lock maker1 a fourth a  
padlock maker1 a fifth a mortice-lock   
maker1 and so on4 ,but a much more      
singular feature is1 that lock-making is
 combined with retail dealing of a      
totally different kind2 thus among the  
occupations put down opposite the names 
of individuals are1 8key-stamper and    
beer-retailer10 8door-lock maker and    
beer-retailer10 8grocer and trunk-lock  
maker10 8,malt-,shovel tavern-keeper and
 rim-lock maker10 8lock-maker and       
provision-dealer10 8grocer and          
key-maker10 8cabinet-lock maker and     
,woolpack tavern10 8key-stamper and     
registrar of births1 c410 8,hope and    
,anchor and cabinet-lock maker10        
8auctioneer and locksmith10 8rim-lock   
and varnish maker10 and so forth4 ,it is
 probable that in some of these cases   
the wife attends to the retail shop1    
while the husband attends to the        
workshop4  ,among all the               
lock-manufacturers of the town there are

 scarcely half a dozen in what may be   
termed a large way of business2 there   
are many who employ from five to fifteen
 pairs of hands1 but the great majority 
are small masters who are themselves    
working mechanics1 and are aided by     
apprentices from one to four in number1 
perhaps two on an average4 ,mr4 ,horne  
thinks that there were not fewer than a 
thousand boys at work in the town1      
chiefly upon locks and keys4 ,the       
children and young persons are employed 
at all ages1 from seven up to manhood2  
from the earliest age1 indeed1 in which 
they are able to hold a file4 ,it is a  
characteristic fact1 where so many of   
the male inhabitants are employed at the
 bench from such early years1 that a    
certain distortion of figure is         
observable2 the right shoulder-blade    
becomes displaced and projects1 and the 
right leg crooks and bends inwards at   
the knee1 like the letter ,k1--it is the
 leg which is hindermost in standing at 
the vice4 ,the right hand also has      

frequently a marked distortion4 8,almost
 every thing it holds takes the position
 of the file4 ,if the poor man carries a
 limp lettuce or a limper mackarel from 
,wolverhampton market1 they are never   
dangled1 but always held like the file4 
,if he carry nothing1 his right hand is 
in just the same position40  ,the hours 
of labour among the small masters are   
scarcely brought within any system at   
all2 for all the work is piecework1 not 
paid for by the day or hour2 and each   
man works as long as he likes1 or as    
long as his business impels him4 ,some  
will file away from four or five in the 
morning till eleven or twelve at night4 
,in the larger shops1 where there are   
many hands employed1 they come to work  
when they like1 leave when they like1   
and do as much work as they like when   
there2 this freedom of action being     
spread over a working-day of perhaps    
sixteen hours4 ,the masters say that the
 men prefer this system1 or want of     
system1 to any thing more precise and   

regular4 ,in the beginning of the week  
there is often much idleness and        
holiday-keeping2 and the ,willenhall men
 make up for this by a day of sixteen1  
eighteen1 or even twenty hours' work    
towards the end of the week4 ,in the    
beginning of the week1 men and boys have
 defined hours and definite periods for 
meals2 but towards the end of the week1 
when hurry and drive are the order of   
the day1 they eat their meals while at  
work1 and bolt their victuals standing4 
8,you see a locksmith and his two       
apprentices1 with a plate before each of
 them1 heaped up 7at the best of times1 
when they can get such things7 with     
potatoes and lumps of something or      
other1 but seldom meat1 and a large     
slice of bread in one hand2 your        
attention is called off for two minutes1
 and on turning round again1 you see the
 man and boys filing at the vice40  ,in 
the processes as carried on at          
,willenhall1 they are applied chiefly to
 the manufacture of mortice1 box1 trunk1

 rim1 cabinet1 case1 bright1 dead1      
closet1 and padlocks4 ,except some of   
the parts of the brass-work1 which are  
cast1 these locks are made by forging1  
pressing1 and filing4 ,the forging is a 
light kind of smith's work1 aided by a  
light hammer and a small pair of        
bellows2 children and young persons are 
largely employed in this process4       
,pressing is a kind of work by which    
certain parts of the lock are pressed or
 stamped out4 ,the presses are of       
various sizes1 but all require much     
strength to work them2 the press has a  
horizontal lever1 crossing the top of a 
vertical screw1 and there is generally  
an iron weight at the end of each arm or
 half of the lever to increase the      
power2 one of the lever arms is grasped 
in the right hand of the presser1 and   
whirled round with a jerk2 while the    
fingers of the left hand place the metal
 in its proper position1 and remove it  
when it has been stamped or pressed4    
,there is1 of course1 a die or cutter   

attached to the press1 to cut the metal 
in the proper form4 ,sometimes the press
 has only one arm to the lever1 and no  
weight at the end of this1 so that the  
labour of working is much increased4    
,children and youths are employed at    
this process1 so far as their strength  
will admit4 ,the last process1 filing1  
is that by which the separate pieces are
 shaped and smoothed for adjustment in  
their proper places2 here children and  
youths are almost exclusively employed2 
they stand upon blocks so as to be able 
to reach the vice1 and then work away   
with the file1 unrelieved by any change 
in the nature of the process4  ,in      
key-making the processes may be said to 
comprise forging1 stamping1 piercing1   
and filing4 ,the forging differs very   
little from that required in making the 
pieces for a lock4 ,the stamping is     
effected by placing the end of an iron  
wire1 taken red-hot from the forge1 into
 one half of a key-mould made in a block
 or kind of anvil2 a heavy weight is    

then raised between an upright          
framework1 in the grooves of which it   
runs by means of a cord2 the cord is    
drawn by both hands1 with the assistance
 of one foot in a stirrup attached to   
the end of the cord2 at the bottom of   
the weight thus raised is the other half
 of the key-mould4 ,such being the      
nature of the stamping apparatus1 the   
process is thus conducted3 the foot in  
the stirrup being suddenly raised1 and  
the cord loosed1 the weight falls upon  
the red-hot wire1 and the blow stamps it
 into the two moulds or half-moulds1    
which are brought accurately together by
 means of the slides or side-grooves in 
the framework4 ,the rough key is also   
trimmed and cleared by the pressing     
apparatus2 that is1 the surplus metal   
all round is cut off by a single blow2  
and the metal which fills up the ring or
 handle of the key is cut or pressed out
 in the same way4 ,this is a heavy part 
of the key-work1 for which the labour of
 men rather than that of boys is        

required4 ,the process of piercing the  
key consists in making the pipe or      
barrel1 required for most keys1 except  
those which are intended to open a lock 
for both sides2 the pipe is drilled by a
 small machine worked with the foot like
 a lathe2 it is a process requiring more
 skill than strength1 relatively to     
other parts of the manufacture4 ,the    
filing of a key is important2 for not   
only is the whole key made bright1 but  
the wards are cut by the file and       
chisel4 ,boys and youths are employed in
 filing the common keys2 but those of   
better quality are entrusted to men4    
,the apprenticeship system is carried on
 to a remarkable extent among the lock  
and key makers of ,willenhall4 ,the     
small masters take apprentices at any   
age at which they can work4 ,some of    
them employ only apprentices1 never     
paying wages for journeymen1 but always 
taking on a new apprentice as soon as a 
former one is out of his time4 ,the boys
 are mostly procured from other towns1  

and they bring with them a small        
apprenticeship-fee and a suit or two of 
clothes4 ,they are bound to the masters 
by legal indenture or contract2 and the 
masters board and lodge and clothe them 
during their apprenticeship4 ,one       
consequence of this system is1 that when
 the apprentice has served his time1 he 
is almost driven to become a small      
master himself from want of employment  
as a journeyman2 and he then takes      
apprentices as his master did before    
him4 ,this accounts for the fact that in
 ,willenhall there are few large        
manufacturers and few journeymen2 while 
there is a constantly-increasing number 
of small masters and of apprentices4    
,the ,willenhall makers nearly all look 
to the ,wolverhampton factors or dealers
 for a market for their wares--so far at
 least as concerns locks and keys2 there
 are some other articles which they sell
 more frequently to ,birmingham houses4 
,the master and an apprentice1 or       
perhaps two1 generally trudge off to    

,wolverhampton on a ,saturday1 bearing  
the stock of locks which he may have to 
sell2 and the money receipts for the    
locks or keys sold are usually in part  
spent at the large market of            
,wolverhampton previous to the homeward 
journey4 ,the ,willenhall men take      
contracts at so low a price as to       
prevent the competition of other places2
 it is stated1 that whatever be prices  
elsewhere1 nothing can come below the   
,willenhall prices for cheap locks4 ,the
 men work hard for small returns1 and   
yet they have a strong yearning for     
their own town4 ,a ,willenhall girl will
 seldom marry except to a townsman2 and 
thus they intermarry to an extent which 
maintains their characteristics as a    
peculiar community4 ,as an example of   
their disinclination to leave their own 
town1 ,mr4 ,horne states the following  
circumstance3 8,some years ago a factor1
 who had projected a manufactory in     
,brussels1 engaged some five-and-twenty 
,willenhall men1 whom he was at the     

expense of taking over4 ,he gave them   
all work1 and from hard-earned wages of 
from #is4 to #aes4 a-week1 these        
#8practised hands' found themselves able
 to earn #cl4 a-week and upwards4 ,but  
they were not satisfied1 and began to   
feel uncomfortable2 first one left1 and 
returned home2 then another2 then one or
 two2 till1 in the course of a few      
weeks1 every man had returned to        
,willenhall0--there to work harder and  
earn less4  ,it is just possible that   
the application of the factory system to
 lock-making may first become important 
by making the best locks cheaper than   
they can be made by the handicraft      
method2 for there seems not much        
probability1 at least for a great length
 of time to come1 that any new system   
will be able to compete with ,willenhall
 in the common locks--those of which    
more thousands are sold than there are  
tens of the better locks4 ,in this1     
however1 it would not do to predict     
rashly4 ,hand-loom weaving is cheap     

enough1 unfortunately for those who     
practise it2 but yet the factory system 
comes down as low as the lowest         
hand-loom weaving4  ,the editor of      
,hebert's ,encyclopdia1 after noticing  
the facilities for opening most locks by
 copying the key1 makes the following   
announcement3 8,it affords the editor of
 this work much satisfaction to state1  
that he has in his possession a lock1   
the key of which cannot be copied1 a    
locksmith possessing no tools by which  
an exactly similar one can be made2 the 
machine by which the original one was   
made is so arranged as to be deprived of
 the power of producing another like it4
 ,the lock is very simple1 very strong1 
and can be very cheaply made4 ,the cost 
of a complete machine to make them would
 be about #ajjl42 with that they might  
be manufactured at one-half the expense 
of any patent lock4 ,the inventor is    
desirous to have the subject brought    
before the public under a patent2 but   
want of time to devote himself to such  

an object at present obliges him to lay 
it aside40 ,the invention not being     
patented1 the editor of course gave no  
diagram or engraving of the lock or     
machine2 nor does there appear to have  
been a patent obtained during the       
sixteen or eighteen years which have    
elapsed since the above notice was      
published4 ,there are1 however1         
mechanical principles sufficiently well 
known to lead to a belief that such a   
machine is practicable2 a               
ticket-printing or numbering machine    
will1 in printing #ajj1jjj tickets1     
produce such variations that no two     
impressions shall be identical2 and a   
key-making machine might1 after         
fashioning a particular part of each    
key1 modify the arrangement of certain  
wheels and pinions so far as to produce 
a slightly different result when the    
next key is to be operated on4  ,in the 
manufacture of locks and keys generally1
 there is no reason why the factory     
system should not1 to a certain extent1 

be applicable4 ,by this will be         
understood1 the production of similar   
parts by tools or machines1 graduated in
 respect to each other with more care   
than can be done by the hand method4 ,if
 we suppose that a lock of particular   
construction comprises twenty screws and
 small pieces of metal1 and that there  
are required1 for general disposal in   
the market1 five sizes of such a lock2  
there would thus be a hundred pieces of 
metal required for the series1 each one 
differing1 either in shape or size1 from
 every one of the others4 ,now1 on the  
factory or manufacturing system1 as     
compared with the handicraft system1    
forging1 drawing1 casting1 stamping1 and
 punching1 would supersede much of the  
filing2 the drilling machine would      
supersede the drill-stock and bow1 and  
other machines would supersede other    
hand-worked tools4 ,this would be       
done--not merely because the work could 
be accomplished more quickly or more    
cheaply--but because an accuracy of     

adjustment would be attained1 such as no
 hand-work could equal1 unless it be    
such special work as would command a    
high rate of payment4 ,for any one size 
in the series1 and any one piece of     
metal in each size of lock1 a standard  
would be obtained which could be copied 
to any extent1 and all the copies would 
be like each other4 ,to pursue our      
illustration1 the manufacturer might    
have a hundred boxes or drawers1 and    
might supply each with a hundred copies 
of the particular piece of metal to     
which it is appropriated1 all so exactly
 alike that any one copy might be taken 
as well as any other4 ,ten pieces1 one  
from each of ten of these boxes1 would  
together form a lock2 ten1 one from each
 of another ten boxes1 would form a     
second lock1 and so on2 and there would 
be1 in the whole of the boxes1 materials
 for a thousand locks of one            
construction1 a hundred of each size4   
,now the advantage of the machine or    
factory mode of producing such articles 

is this1 that they can be made in large 
numbers at one time1 whenever the       
steam-engine is at work2 and that when  
so made1 the pieces are shaped so       
exactly alike1 the screws have threads  
so identical1 and the holes are bored so
 equal in diameter1 that any one of a   
hundred copies would act precisely like 
all the others1 thereby giving great    
advantages to the men employed in       
putting the lock together4  ,these      
principles are being applied by ,messrs4
 ,hobbs and ,co4 in their ,london       
establishment4 ,a number of machines1   
worked by steam-power1 are employed in  
shaping the several pieces of metal     
contained in a lock2 and all the several
 pieces are deposited in labelled       
compartments1 one to each kind of piece4
 ,the machines are employed--in some    
cases to do coarse work1 which they can 
accomplish more quickly than it can be  
done by men2 and in other cases to do   
delicate work1 which they can accomplish
 more accurately than men2 but so far is

 this from converting the men into      
lowly-paid automatons 7as some might    
suppose71 that the manufacturers are    
better able to pay good wages for the   
handicraft labour necessary in putting  
the locks together1 than for forming the
 separate parts by hand2 just as the    
8watchmaker10 as he is called1 who puts 
the separate parts of the watch         
together1 is a better-paid mechanic than
 the man who is engaged in fabricating  
any particular parts of the watch4  ,it 
may be observed that the system of      
manufacturing on a large scale1 by many 
men engaged in one large building1 is   
more nearly universal in the ,united    
,states than in ,england4 ,the workshop 
system1 as pursued at ,willenhall by the
 lock-makers1 is very little practised  
in ,america4 ,being comparatively a new 
community1 and being at liberty to      
select for imitation or for improvement 
whichever of the usages or systems in   
the old country they may prefer1 the    
,americans have preferred to adopt the  

factory system rather than the workshop 
system1 and to carry out the former to  
an extent not yet equalled in           
,england--not yet equalled1 we mean1 in 
the number of trades to which it is     
applied4     ,,chapter ,,xii4  ,,english
 ,,patents ,,for ,,locks--,,aubin',s    
,,lock ,,trophy4   ,we propose to       
conclude this small work with a few     
details respecting the various patented 
inventions in locks1 and concerning ,mr4
 ,aubin's remarkable lock trophy4 ,these
 two subjects relate to locks in        
general1 rather than to any specified   
constructions in particular1 and can on 
that account more conveniently be given 
here than in connexion with any of the  
foregoing chapters4  ,mr4 ,chubb1 in the
 appendix to his paper on locks and keys
 read before the ,institution of ,civil 
,engineers1 gave a useful list of all   
the patents taken out in ,england in    
relation to this subject1 down to the   
year #ahdi4 ,we here transcribe this    
list3  ,list of ,patents for ,locks and 

,latches granted since the              
,establishment of the ,patent ,laws4    
8,as no complete list of the patents    
granted for locks from the time of      
,james ,i4 has hitherto been published1 
it is believed that the following list1 
which has been very carefully drawn up1 
and which comprises all patents from the
 year #aggd1 when the first patent for a
 lock was granted1 to the present time1 
will be found useful as a reference for 
all who are interested in the subject4  
#aggd,may       #bg;,black1 ,george1    
,berwick-on-,tweed4                     
,barron1 ,robert1 ,london4   #aggh,may  
#bi,martin1 ,joshua ,lover1             
,fleet-street1 ,london4   #aggi,may     
#bh;,henry1 ,solomon1 ,swithin's-lane1  
,london4   #aghj,march      #d;,campion1
 ,j4 ,newcastle-court1 ,strand1 ,london4
   #aghb;,january   #ah;,hutchinson1    
,samuel1 ,marylebone1 ,london4   #aghd  
,bramah1 ,joseph1 ,piccadilly1 ,london4 
#aghi;,july       #g;,cornthwaite1      
,thomas1 ,kendal1 ,westmoreland4        

#agij;,february  #bc,rowntree1 ,thomas1 
,surrey-street1 ,blackfriars1           
,london4      ,october   #bi;,bird1     
,moses1 ,wardour-street1 ,london4       
#agia;,july      #ai;,ferryman1 ,rev4   
,robert1 ,gloucester4      ,november    
#c;,antis1 ,john1 ,fulneck1 near ,leeds4
   #agig,november  #ah,langton1 ,daniel4
   #agih,may        #c;,bramah1 ,joseph4
      ,december   #h,turner1 ,thomas4   
#agii;,april     #aa;,davis1 ,george4   
#ahja;,february  #aj,scott1 ,richard1   
,lieut4-,colonel4      ,june            
#bd;,holemberg1 ,samuel1 ,london4       
444         ,roux1 ,albert1             
,switzerland4   #ahje,may               
#ah,stansbury1 ,abraham ,ogier1 ,new    
,york4      ,december  #bi,thompson1    
,william1 ,birmingham4   #ahae,march    
#g,mitchell1 ,william1 ,glasgow2 and    
,lawton1 ,john1                         
,london4   #ahaf,may       #ad,ruxton1  
,thomas1 ,esq41 ,dublin4                
#ahag;,february   #h;,clark1 ,william1  
,esq41 ,bath4   #ahah;,february         

#c;,chubb1 ,jeremiah1 ,portsea4         
#ahai,october   #ah,strutt1 ,anthony    
,radford1 ,mackeney4   #ahbj;,april     
#aa;,jennings1 ,henry ,constantine1     
,esq41 ,middlesex4      ,december       
#ad,mallett1 ,william1 ,dublin4         
#ahbc;,july      #aj;,fairbanks1        
,stephen1 ,middlesex4      ,november    
#ac,ward1 ,john1 ,middlesex4            
#ahbd;,june      #ae;,chubb1 ,charles1  
,portsea4   #ahbe,may       #ad,young1  
,john1 ,wolverhampton4   #ahbh,may      
#ag;,chubb1 ,charles1 ,london4          
#ahbi;,june       #a;,gottlieb1 ,andrew1
 ,middlesex4   #ahcj;,january           
#ah;,carpenter1 ,james1 and ,young1     
,john1 ,wolverhampton4      ,january    
#bf;,arnold1 ,john1 ,sheffield4         
#ahca;,april     #ad,rutherford1        
,william1 ,jedburgh1 ,n4,b4      ,may   
#bc;,barnard1 ,george1 ,bristol4        
,july      #bg,young1 ,john1            
,wolverhampton4   #ahcb;,december       
#bj,parsons1 ,thomas1 ,london4          
#ahcc;,december   #c,parsons1 ,t41      

,newport1 ,salop4      ,december        
#bj;,chubb1 ,charles1 ,london2 and      
,hunter1 ,e41                           
,wolverhampton4   #ahcd,september       
#f,longfield1 ,william1 ,otley4         
,october   #aa;,audley1 ,lord ,baron    
,stafford4   #ahce,march     #ah;,hill1 
,r41 ,birmingham4      ,december        
#af,warwick1 ,j41 ,london4              
#ahcf;,february  #aj;,fenton1 ,rev4 ,s41
 ,pembroke4   #ahch;,june               
#cj,uzielli1 ,m41 ,london4              
,november  #ac,thompson1 ,s41 ,london4  
#ahci;,february  #ba,uzielli1 ,m41      
,london4      ,june      #ab,sanders1   
,j4 ,stafford4      ,july               
#c;,cochrane1 ,a41 ,strand1 ,london4    
,july      #bj,schwieso1 ,j4 ,c41       
,london4      ,august     #a,williams1  
,w4 ,m41 ,london4      ,december        
#b;,guest1 ,j41 jun41 ,birmingham4      
#ahdj;,february  #bg,williams1 ,w4 ,m41 
,london4      ,march     #bj;,gerish1   
,f4 ,w4      ,may        #b,pearse1 ,w41
 ,hoxton1 ,middlesex4      ,june        

#ac,wolverson1 ,j41 and ,rawlett1 ,w41  
,stafford4      ,october   #bb;,clark1  
,t4      ,december  #bc;,baillie1 ,b41  
,london4   #ahda,march     #bi,tildesley
 and ,sanders1 ,willenhall and          
,wolverhampton4   #ahda,may             
#f;,hancock1 ,james1 ,sidney-square1    
,mile ,end4      ,july      #ad;,berry1 
,miles1 ,chancery-lane4      ,september 
#bh,strong1 ,theodore ,frederick1       
,goswell-road4      ,november           
#i,smith1 ,jesse1 ,wolverhampton4       
#ahdb;,january   #ae,poole1 ,moses1     
,lincoln's-inn4      ,may               
#bd;,duce1 ,joseph1 ,wolverhampton4     
,june       #a,williams1 ,w4 ,m41 #afc  
,fenchurch-street4      ,december       
#bi,rock1 ,joseph1 jun41 ,birmingham4   
#ahdc,november  #be,tann1 ,e4 ,e4 and   
,j41 ,hackney-road4                     
,rock1 ,joseph1 jun41 ,birmingham4      
#ahdd;,july      #cj;,fletcher1 ,rev4   
,william1 ,moreton ,house1 ,buckingham4 
#ahde;,april     #ae;,carter1 ,george1  
,willenhall4      ,july                 

#ab,ratcliff1 ,edmund1 ,birmingham4     
,december   #d,poole1 ,moses1           
,lincoln's-inn4      ,december          
#bb,smith1 ,philip1 ,high-street1       
,lambeth4   #ahdf;,july       #f;,de la 
,fons1 ,john ,palmer1 ,carleton-hill1   
,st4 ,john's                   ,wood4   
,july      #ae,thomas1 ,william1        
,cheapside4      ,december  #ad;,chubb1 
,john1 ,st4 ,paul's ,churchyard4        
#ahdg;,january   #aa;,chubb1 ,john1 and 
,hunter1 ,ebenezer1 sen41 ,st4 ,paul's  
,churchyard4      ,april                
#ae;,collett1 ,charles ,minors1 #fb     
,chancery-lane4   #ahdh,september       
#bh,newall1 ,robert ,stirling1          
,gateshead4   #ahdi,may                 
#h,wilkes1 ,samuel1 ,wednesbury-heath1  
,wolverhampton4  ,mr4 ,chubb also gave a
 list of such papers m the ,transactions
 of the ,society of ,arts as refer to   
locks and keys4  ,list of ,references to
 the 8,transactions of the ,society of  
,arts10 on the subject of ,locks4       
vol4 page4    #a4   #cag  ,mr4 ,moore4  

#b4   #ahg     ,cornthwaite4    #c4     
#afj  ,marquis of ,worcester4           
#afe  ,mr4 ,taylor4        #afc         
,marshall4   #ah4   #bci     ,t4        
,arkwright4        #bdc     ,bullock4   
#ai4   #bij     ,w4 ,bullock4   #cf4    
#aaa     ,m4 ,somerford4   #ch4   #aaa  
,a4 ,ainger4        #bje     ,bramah4   
#db4   #abe     ,j4 ,duce4   #dc4   #aad
     ,w4 ,friend4   #de4   #abc         
,machin4   #dh4   #acb     ,s4 ,mordan4 
#ej4    #hf     ,a4 ,mackinnon4   #ea4  
#abh     ,j4 ,meighan4  ,among the most 
curious mechanical productions in the   
,great ,exhibition of #ahea1 was one    
which attracted very little notice1 viz4
 that forwarded by ,mr4 ,c4 ,aubin of   
,wolverhampton4 ,whether it was that    
attention1 so far as regards locks1 was 
too much absorbed by the 8lock          
controversy10 or whether there was a    
deficiency of descriptive cataloguing1  
no juror or newspaper critic1 as far as 
we are aware1 took notice of the        
production in question4 ,in the         

,official ,illustrated ,catalogue it is 
entered simply as 8,specimens to        
illustrate the rise and progress of the 
art of making locks1 containing         
forty-four different movements by the   
most celebrated inventors in the lock   
trade40 ,this trophy of lock ingenuity  
7for such it may be justly considered to
 be7 is now in the possession of ,mr4   
,hobbs4 ,springing from a hexagonal     
base-piece is a central axis1 about     
three feet in height1 supporting four   
horizontal circular discs1 placed at    
different parts of its height4 ,each of 
the vertical faces of the base-piece    
contains a lock1 which is worked by its 
respective key4 ,each disc contains a   
number of locks3 #af on the lowest1 #ab 
on the next above1 #i on the third in   
height1 while a ,bramah lock surmounts  
the whole4 ,all the locks on the discs  
are so arranged that their bolts shoot  
outwards1 or radially away from the axis
 of the machine4 ,every lock has its own
 proper key inserted in the key-hole2   

and as the locks lie down horizontally1 
the shaft of each key is of course      
vertical4 ,there are delicate pieces of 
mechanism contained within the central  
axis and within the discs1 consisting of
 levers1 racks1 and pinions2 and the    
,bramah lock is contrived so            
ingeniously1 that the ,bramah key1 by   
acting upon that lock1 acts upon all    
this mechanism4 ,the ,bramah barrel1 in 
rotating horizontally under the action  
of its key1 gives a rotary movement to a
 rod passing vertically through the     
centre of the whole apparatus2 this rod1
 at the levels of the several discs1    
acts upon racks and pinions1 and these  
in turn act upon the key-pins of the    
several locks4 ,when1 therefore1 the    
,bramah key is turned1 the whole of     
these key-pins rotate1 each exactly in  
the same way as if the lock were being  
closed or opened1 and the bolts shoot in
 or out accordingly4 ,the ,bramah key1  
although it acts as a master-key1 is not
 such as usually obtains that           

designation2 it is simply a means of    
putting in action certain               
rack-and-pinion mechanism1 which does   
not belong to lock-work considered per  
se4 ,all the locks are faithful         
representatives of the several patents  
or modes of construction to which they  
severally refer2 and each exhibits the  
works sufficiently open to display the  
principle on which it is arranged4 ,each
 lock is numbered1 and is referred to in
 an accompanying description4 ,the works
 are finished with the utmost care and  
polish2 and the trophy being somewhat   
tastefully arranged1 and kept under a   
glass shade1 forms a really elegant     
specimen of mechanical skill4  ,for an  
account of the locks themselves which   
constitute this trophy1 we cannot do    
better than avail ourselves of the      
description given in the article 8,lock0
 in ,tomlinson's ,cyclopdia of ,useful  
,arts1 adding a few further details in  
respect to some of the locks of the     
series4 ,the locks are arranged and     

numbered according to their similarity  
of construction2 and it is instructive  
to remark the evidence here afforded1   
that many patentees would have saved    
much time and money if they had better  
known the productions of their          
predecessors4 ,in describing these locks
 we shall do so briefly1 sufficient to  
shew their relative principles of       
construction2 many of them having been  
described more or less fully in former  
chapters4  ,no4 #a on the list is called
 a ,roman lock2 it consists of a single 
bolt1 with a binder-spring for holding  
the bolt in any position in which it may
 be placed until a sufficient force is  
applied to overcome it3 it embodies the 
simple principle on which thousands of  
common locks are annually made4  ,no4   
#b1 called a ,french lock 7all such     
designations are of rather doubtful     
correctness71 resembling ,no4 #a in     
every thing except having the addition  
of a friction-roller4 ,the bolt of      
either of these two locks can easily be 

forced back by pressing on the end4     
,no4 #c is marked ,ancient2 it is a     
bolt-lock1 and was found in an ancient  
building4 ,it exhibits an improvement on
 both the former specimens1 in so far as
 the bolt requires1 before it can be    
shot1 to be pressed down1 in order to   
release it from a catch at the back end 
of the bolt2 this release cannot be     
effected without the aid of a key or    
some other implement applied through the
 key-hole1 and thus the bolt answers the
 purpose both of bolt and tumbler4  ,no4
 #d1 also marked ,ancient1 is in        
principle a single-acting tumbler-lock2 
that is1 one in which the tumbler may   
fail to be lifted high enough1 but      
cannot be raised too high1 to release   
the bolt3 whereas a double-acting       
tumbler1 being susceptible both of too  
much and too little ascent1 must be     
raised to one definite and precise      
height to attain the required object4   
,no4 #e1 an old ,english lock1 exhibits 
a great advance in principle1 being     

provided with the double action just    
described as being wanting in ,no4 #d4  
,no4 #f1 modern ,english 7no maker's    
name71 is a single-acting tumbler-lock4 
,no4 #g1 by ,mace1 is a double-acting   
tumbler1 but without exhibiting any     
peculiarities of construction4  ,no4 #h 
is ,somerford's first patent4 ,it is a  
double-acting draw tumbler-lock2 that   
is1 there is a tumbler which is drawn   
down instead of being lifted1 as in most
 locks4  ,no4 #i1 designated1 we know   
not on what grounds1 an ,indian lock1   
has a single-acting tumbler with a pin4 
,no4 #aj1 patented by ,thompson in      
#ahje4 ,in this lock there are two      
tumblers1 one of which is single and the
 other double-acting4  ,next follow a   
considerable number of locks1 which     
differ one from another too slightly to 
render any formal description necessary4
 ,no4 #aa1 by ,daniells1 is a           
single-acting tumbler1 differing only in
 form from those previously used4 ,no4  
#ab is by ,walton4 ,no4 #ac is ,barron's

 first patent1 taken out in #aggd4 ,no4 
#ad is by ,bickerton4 ,no4 #ae is a     
,dutch lock4 ,no4 #af is by ,duce1      
senior4 ,no4 #ag1 by ,sanders1 is a lock
 with four double-acting tumblers4 ,no4 
#ah1 patented by ,cornthwaite in #aghi1 
is so nearly like ,sanders's1 brought   
before public notice in #ahci1 as to    
corroborate what we have said concerning
 the identity1 or at least close        
resemblance1 of inventions widely       
asunder in point of time4 ,no4 #ai is by
 ,richards and ,peers4  ,no4 #bj is     
,somerford's second patent2 a lock which
 seems to embody the principle of ,mr4  
,tann's 8reliance-wards10 patented many 
years later4 ,no4 #ba is ,rowntree's    
lock1 patented in #agij4 ,no4 #bb is the
 first patent lock of ,duce1 junior1    
dated #ahbc4 ,no4 #bc is ,parsons' first
 patent1 of #ahcb4 ,no4 #bd is          
,bickerton's second4 ,no4 #be1 patented 
by ,price in #aggd2 this1 so far as at  
present appears1 was the first lock ever
 constructed with four double-acting    

tumblers1 bearing a closer resemblance  
than would generally be supposed to     
those patented by other persons in more 
recent years4 ,no4 #bf exhibits a       
somewhat similar coincidence4 ,it was   
introduced by ,aubin in #ahcj1 and is   
furnished with a revolving curtain for  
the purpose of closing the key-hole     
during the revolution of the key4 ,other
 inventors have since then adopted the  
revolving curtain2 and in a patent taken
 out so recently as #aheb1 this         
appendage is claimed as part of the     
patent4  ,no4 #bg is ,barron's second   
patent1 dated #aggh2 a lock which has   
perhaps been the model for a larger     
manufacture of plain simple             
tumbler-locks than any other4 ,no4 #bh  
is by ,bird1 #agij4 ,no4 #bi is the     
second patent of ,duce1 junior4 ,no4 #cj
 is ,ruxton's1 #ahah4 ,no4 #ca is       
,chubb's simplified lock1 #ahcd4 ,no4   
#cb is by ,marr4 ,no4 #cc1 by ,tann1 is 
the 8reliance-ward0 lock adverted to    
above as having been anticipated1 in    

respect to its leading principle1 by    
,somerford's second patent4 ,no4 #cd is 
by ,hunter1 #ahcc4 ,no4 #ce is ,parsons'
 second patent1 of the same year4 ,no4  
#cf is by ,lang1 #ahcj4 ,no4 #cg is     
,lawton's1 dated #ahae4 ,no4 #ch1       
patented by ,strutt in #ahci1 has an    
arrangement for holding the tumblers1 in
 the event of a pressure being applied  
to the bolt2 an arrangement bearing a   
considerable resemblance to one recently
 adopted in ,chubb's bankers' lock4 ,no4
 #ci is by ,scott1 #ahae4 ,no4 #dj1     
,chubb's patent of #ahah1 is the        
original detector-lock of this maker4   
,most of the detectors since patented by
 various persons are little other than  
variations of ,chubb's original4  ,no4  
#da1 ,parsons' third patent of #ahcc1 is
 a changeable lock of peculiar          
construction4 ,the elevation of the     
tumblers is regulated by an             
adjusting-screw passing through the lock
 to the inside of the door2 this screw  
changes the positive but not the        

relative positions of the tumblers2 so  
that the same difference in the steps of
 the key must be retained1 the change   
being made only in the length of the    
bit3 the number of changes for each lock
 is very limited4  ,no4 #db1 invented by
 ,pierce in #ahdj1 seems to be a        
carrying out of the plan suggested by   
the ,marquis of ,worcester in his       
,century of ,inventions1 where he says  
that 8a lock may be so constructed that 
if a stranger attempteth to open it1 it 
catches his hand as a trap catcheth a   
fox2 though far from maiming him for    
life1 yet marketh him so1 that if once  
suspected he might easily be detected40 
,in ,pierce's lock a steel barb or sharp
 arrow-head is concealed below the      
key-hole1 in such a manner that if any  
person in attempting to open the lock   
should over-lift the tumbler1 the barb  
would be thrust by a spring into his    
hand4 ,it is said that the patentee     
himself experienced the efficacy of this
 invention1 by receiving the barb into  

his own hand4  ,no4 #dc1 by ,ruxton1    
patented in #ahaf1 is furnished with a  
tell-tale1 so arranged that if the      
tumbler be over-lifted in an attempt to 
pick the lock1 a pin or catch is thrown 
out from the lock1 which would be       
visible on opening the lock with the    
proper key4 ,this invention preceded    
,chubb's detector by two years1 and     
would be entitled to some of the honours
 of originality were not ,chubb's       
arrangement much more simple and        
effective4  ,no4 #dd is ,bramah's1 the  
patent of #aghd1 and the crowning lock  
of the trophy1 by which all the others  
are opened4 ,similar locks by ,russell  
and ,mordan are applications of the     
,bramah principle1 with little or no    
variation4         99       99       99 
99       99  ,no attempt has been made  
in these pages to describe every variety
 of lock that has been introduced4      
,several forms of puzzle locks1 known as
 ,russian and ,chinese locks1 have the  
forms of various animals1 and they are  

locked and unlocked by pressing upon or 
moving some portion of the body of the  
animal3 the security of such locks      
depends in many cases upon keeping the  
part to be pressed or moved secret4     
,there are also various forms of alarum 
locks2 but these do not greatly differ  
from common locks1 except in having     
certain appendages1 such as a pistol1   
which if loaded and properly adjusted1  
will be fired on any attempt being made 
to open the lock1 either with its own   
key or some other instrument4 ,some     
locks are furnished with a bell or a    
rattle1 which is rung or sprung on      
attempting to open the lock1 and in this
 way the inmates of the house are       
informed of the attempt to effect an    
entrance4 ,it will1 however1 be evident 
to any one who has read the preceding   
pages1 that devices of this kind do not 
add to the security of the lock2 they   
rather tend to degrade the art of the   
locksmith to that of the toyman4 ,the   
locksmith1 in common with every other   

artist1 can only improve in his art by  
studying the principles upon which it   
rests1 and illustrating them by the most
 approved examples which the            
constructive genius of his predecessors 
or contemporaries has furnished4        
,,appendix4   ,,chapter ,,xiii4  ,,on   
,,an ,,improved ,,construction ,,of     
,,lock ,,and ,,key4#ab    #ab ,by ,j4   
,beverley ,fenby1 ,mechanical ,engineer1
 of ,birmingham4   ,extracted chiefly   
from the ,proceedings of the            
,institution of   ,mechanical           
,engineers1 #ahff4  ,the simple         
fixed-guard or warded lock is so utterly
 worthless for security1 no matter what 
amount of good workmanship be bestowed  
upon it1 that it demands but short      
notice4 ,it was contrived with the      
intention of making the passage to the  
bolt intricate2 but it will be seen at  
once that this intricacy does not really
 offer any security4 ,the wards of a    
lock are circular arcs of thin metal1 so
 arranged as to require a key of        

peculiar pattern to pass amongst them1  
the shape of the cuts in the key being a
 section of the wards4 ,to make a really
 complicated box of wards1 and to cut   
keys which shall accurately fit their   
sweep1 is a matter requiring            
considerable manual dexterity2 and some 
warded locks are therefore expensive4   
,but even with the best of them1 all    
that it is necessary to do for opening  
the lock is to take a blank key which   
will properly fit the keyhole1 coat it  
with wax1 and then inserting it in the  
lock1 press it round against the wards1 
which will cause them to leave an       
accurate impression of their section on 
the key4 ,the parts impressed are then  
cut out with small files1 drills1 and   
saws1 and the occasional use of fine    
cross-cut chisels4 ,the key will then   
pass those wards which impressed        
themselves upon it2 and if these are the
 only wards1 it will go completely round
 and open the lock4 ,if there are also  
other wards in addition1 not brought up 

flush with the first wards1 the key is  
waxed again and pressed against them1   
and then further cut out1 as before4    
,this process is evidently one of       
absolute certainty1 and the key so made 
is in all respects as capable of        
mastering the lock as the original key4 
,these warded locks are however easily  
opened with merely a piece of bent steel
 wire1--bent into such a sweep as will  
reach right round the wards instead of  
passing amongst them1 thus escaping all 
chance of being obstructed by them4     
,such an instrument is called by        
burglars a 8twirl40  ,the fixed-guard or
 warded lock was the one in general use 
in the middle ages4  ,the next kind of  
lock is the tumbler lock1 in which the  
bolt is moved backwards and forwards by 
the key as usual1 but these movements   
cannot take place till a small lever    
with a stump on one side be lifted4     
,this lever and stump form the tumbler1 
which is held down by a spring2 and in  
the tail of the bolt are two notches1   

into one of which the stump fits when   
the bolt is shot1 and into the other    
when it is withdrawn4 ,all that is      
necessary to effect the picking of this 
lock is to lift the tumbler high enough 
for clearing the stump out of the notch1
 and then draw back the bolt4 ,the      
tumbler may be lifted with one pick1 and
 the bolt drawn back with another2 but  
generally one pick will suffice for both
 purposes4  ,in the ,barron tumbler lock
 the principle of double-action was     
introduced4  ,the next improvement was  
the lever lock properly so called1 under
 which designation the majority of the  
modern locks may be classed4  ,the      
,bramah lock was an admirable           
contrivance with remarkably beautiful   
mechanism contained in a small compass2 
and since its invention there have been 
several ingenious modifications of the  
same principle in different radial      
locks1 such as the ,yale lock1 in which 
the slides move radially instead of     
axially4 ,one advantage in these radial 

locks is the greater difficulty in      
copying the keys1 in comparison with the
 flat keys of ordinary lever locks3 this
 difficulty however is not an           
insurmountable one4  ,a very ingenious  
addition was made to the action of the  
lever lock in ,newell's ,american lock1 
which was shown in the #ahea            
,exhibition1 and described at page #hi  
of the present volume4  ,though locks   
such as those already referred to       
exhibit great dissimilarity of          
construction1 yet there is one point in 
which they all agree1 and that is in the
 possession of a direct passage from the
 outside to the works4 ,although various
 locks have been devised with the object
 of having no direct passage to the     
works from the outside1 one             
consideration shows the inevitable      
existence of such a passage2 namely1    
that without it the key could not       
possibly at one and the same time touch 
the hand of the operator and the works  
of the lock4 ,it therefore follows that 

any instrument which can pass in the    
same space as the key may be brought to 
bear on the works1 whatever may be their
 construction4  ,it can now be shown    
that1 if picking instruments are thus   
brought to bear on the works through the
 keyhole1 there is a regular tentative  
system whereby the picking of any lock  
with an open keyhole can sooner or later
 be effected4  ,from the foregoing      
observations it is evident that there   
are two important defects in the        
principle of the previous lever locks1  
which being defects in principle are    
fatal to their security2 namely1 the    
means of access to the works of the lock
 through the keyhole1 allowing of a     
series of attempts being made to open   
the lock by picking instruments2 and    
also the facility afforded for repeating
 the trial of a false key made from a   
wax impression of the true key1 and thus
 perfecting it by successive alterations
 after trial4 ,in consequence of the    
possibility thus allowed of making these

 successive attempts either by picking  
instruments or by a false key1 it has   
been shown by the cases that have       
occurred of locks of the best makes     
which have been falsely opened1 that1   
however numerous and complicated may be 
the secondary impediments introduced    
into these locks1 there can be no real  
security against the ultimate success of
 sufficiently numerous and persevering  
attempts1 except by the adoption of some
 new principle of construction specially
 meeting the above two defects4         
,illustration3 fig4 #ec4  ,in the       
invention of the ,improved ,lock and    
,key now to be described1 and which has 
been termed the adytic lock1#ac the     
writer's object has been to meet this   
requirement4 ,in fig4 #ec is shown an   
elevation of this lock1 such as is made 
for an iron safe2 two of the front cover
 plates being removed to show the       
construction4    #ac ,from the ,greek 1 
inaccessible4  ,the head ,b of the main 
bolt is of such a thickness as to be    

flush with the face of the levers ,l and
 guard ,a2 and the strap or tail ,d of  
the bolt is thin1 and passes behind the 
levers and guard1 and also behind the   
plate ,h ,h4 ,the part of the tail ,d   
which would lie under the levers ,l and 
cylinder ,c is removed1 as seen in fig4 
#ed1 and replaced by a separate flat    
plate or stump-bolt1 carrying the stump 
,s4 ,this stump-bolt has a projection ,k
 upon it1 let into a recess in the tail 
,d of the main bolt1 but with th inch   
vertical play in the recess4 ,a spring  
in the tail of the main bolt presses the
 stump-bolt downwards1 keeping the stump
 ,s in the notches of the levers ,l1 as 
shown in fig4 #ec4 ,the stump-bolt can  
thus descend th inch at first without   
moving the main bolt1 and this amount of
 vertical movement is sufficient to     
carry the stump in and out of the       
notches in the levers2 but the          
stump-bolt cannot descend further       
without taking the main bolt with it4   
,illustration3 fig4 #ed4  ,illustration3

 fig4 #ee4  ,immediately in front of the
 bolts comes the fixed plate ,h ,h1 in  
which is cut the cam groove shown by the
 dotted line ,j ,j2 and also the        
vertical slot ,e for the pin ,p to work 
through1 together with another vertical 
slot in which the stump ,s fits and     
works4 ,this plate carries the centre   
pin ,u on which the levers ,l turn4 ,the
 levers are six in number1 though any   
other number may be used2 and they      
occupy collectively ths inch thickness4 
,in front of the plate ,h is fixed the  
guard ,a1 which is made of iron or      
steel1 and has the brass cylinder ,c    
ground into it4 ,the guard is made a    
shade thicker than the levers ,l1 in    
order to prevent the back plate ,h and  
the corresponding front plate from being
 so tightened on the levers as to impede
 their freedom of movement4 ,the        
cylinder ,c is the same thickness as the
 levers1 excepting the centre boss ,f1  
which projects from the back of the     
cylinder and works in a bearing in the  

back plate ,h1 and also projects in     
front through the thickness of the two  
front cover plates4 ,the small keyhole  
in the centre of the boss goes only a   
short distance into the cylinder ,c1    
being merely for the purpose of enabling
 the stem of the key ,m1 fig4 #ee1 to   
turn the cylinder2 the bit of the key is
 a separate piece1 ,n1 fig4 #eg1 which  
is inserted through a separate keyhole  
into the radial slot of the revolving   
cylinder ,c1 as shown at ,n in fig4 #ec4
  ,this radial slot is cut in the side  
of the cylinder ,c that is furthest from
 the levers when the cylinder is in the 
position shown in fig4 #ec2 and in the  
slot fits the slide block ,r1 which is a
 steel block having a pin projecting on 
each side4 ,the back pin enters the     
guide groove ,j ,j in the back plate ,h1
 as shown by the dotted line1 and the   
front pin enters the corresponding guide
 groove in the front cover plate1 which 
is shown removed4 ,the back pin of the  
slide block projects through the back   

plate ,h1 as shown in fig4 #ef1 and     
works in the cam groove ,o in the tail  
of the stump-bolt ,s1 fig4 #ed1 which is
 so shaped that as the slide block      
travels round the guide groove ,j ,j1   
shown by the dotted lines1 it moves the 
stump-bolt vertically as may be required
 according to the position of the bolts 
and levers4  ,illustration3 fig4 #ef4   
,in the position of the lock shown in   
fig4 #ec1 the bit ,n has been inserted  
into the vacant space of the radial slot
 in the cylinder ,c1 in front of the    
slide block ,r4 ,the size of this vacant
 space is ths inch long by th inch wide 
and ths inch deep2 and in the two front 
cover plates of the lock1 and also in   
the door to which the lock is attached1 
a hole is made of the same shape4 ,in   
the door there is no bearing for the    
centre boss ,f1 but only a small keyhole
 corresponding in size with that in the 
boss ,f for inserting the stem of the   
key4         99       99       99       
99       99  ,in the position of the    

parts shown in fig4 #ec1 it will be seen
 that the levers ,l are held pressing   
down against the circumference of the   
cylinder ,c by their springs ,i bearing 
against the pin ,p4 ,in this position   
also the bolt spring between the main   
bolt and the stump-bolt1 fig4 #ed1      
presses the stump ,s down into the      
notches of the levers1 so that the      
levers are completely locked by the     
stump1 as seen in fig4 #ec4  ,in order  
to unlock the lock1 which in fig4 #ec is
 shown with the bolt shot1 it is        
necessary that all the gatings ,g in the
 levers should be brought precisely     
under the stump ,s4 ,through the centre 
keyhole ,f there is no communication    
possible at any time with the levers ,l2
 nor will any instrument1 however       
slender1 if passed into the radial slot 
through the aperture at ,n be able to   
reach them1 whether the cylinder ,c be  
in the position shown in fig4 #ec or    
turned round into any other position4   
,for the only difference made by turning

 the solid cylinder ,c is that the      
radial slot in it is carried away from  
the aperture in the external plates1 and
 the solid part of the cylinder is      
brought opposite to the aperture1 which 
is thereby completely closed against the
 insertion of a picking instrument4     
,this construction accordingly not only 
precludes the possibility of opening    
this lock with an ordinary key1 in which
 the part that acts on the levers is    
attached to the stem of the key1 but it 
also renders it an absolute             
impossibility to introduce a pick of any
 form1 as nothing can reach the levers  
,l except a detached piece of such a    
size and shape as to be capable of      
travelling round in the vacant space    
left in front of the slide block ,r in  
the radial slot of the cylinder ,c4     
,illustration3 fig4 #eg4  ,for the      
purpose of unlocking the lock the bit   
,n1 fig4 #eg1 is used4 ,this bit is of  
such a size as to fit into the vacant   
space of      inch in the radial slot of

 the cylinder ,c2 and the indent at ,v  
is merely for the purpose of ensuring   
the insertion of the bit in the right   
direction1 the external aperture for the
 bit being made with a corresponding    
projection to fit the indent in the bit4
 ,this bit being inserted through the   
aperture in the door1 is pushed in by   
means of the key stem ,m1 which is      
flattened on two sides for that purpose1
 as shown in fig4 #ee2 and the bit is   
thus pushed home into its place in the  
radial slot of the cylinder1 as shown at
 ,n1 fig4 #ec4  ,the key stem ,m is now 
inserted into the centre keyhole ,f1 and
 the cylinder is turned round by it in  
the direction shown by the arrow1       
carrying round the slide block ,r and   
the bit ,n4 ,the slide block ,r1 while  
moving through the concentric portion at
 the commencement of the guide grooves  
,j ,j1 does not affect the bit2 but by  
means of the cam groove ,o in the tail  
of the stump-bolt1 fig4 #ed1 it moves   
that bolt so far as to lift the stump ,s

 completely out of the notches in the   
levers ,l1 which are thereby left free  
to be raised4 ,on continuing to turn the
 cylinder ,c1 the eccentric part of the 
guide grooves ,j ,j causes the slide    
block ,r to move outwards along the     
radial slot1 pushing the bit ,n before  
it2 and the bit is thus made to project 
beyond the circumference of the         
cylinder1 which it can then do1 being no
 longer confined by the guard ,a4 ,the  
further projection of the bit as the    
cylinder revolves causes the steps in   
the bit to lift their respective levers2
 and the steps in the bit are so        
arranged that1 when the cylinder arrives
 at the position shown in fig4 #eh1 all 
the gatings ,g are brought              
simultaneously opposite the stump ,s1   
which is instantly shot down through the
 distance of the th inch play by the    
bolt spring4 ,the bit ,n remains in     
contact with the extreme part ,t of the 
levers while the stump ,s is entering   
the gatings1 the action of the bolt     

spring being so rapid that the bit      
cannot move through any appreciable     
distance during the time4               
,illustration3 fig4 #eh4  ,in other     
locks a spring action of this kind would
 greatly facilitate the picking1        
inasmuch as it would afford the gentle  
uniform pressure desired upon the       
levers4 ,in other locks1 therefore1 the 
bolt is caused to move1 and the stump to
 enter the gatings1 by the direct       
contact of the key with the bolt1       
instead of by a spring2 but as the key1 
while moving the stump into the gatings1
 is also altering its position under the
 levers1 a slight tremulous motion of   
the levers is thereby occasioned1 which 
no care in manufacture can obviate4     
,this tremulous motion is aggravated by 
the circumstance that1 as the keyhole is
 open to inspection1 it is necessary to 
make all the levers fit flush with one  
another when down1 in order to avoid    
affording any clue to the shape of the  
key from the positions of the levers2   

but as the various steps of the key1    
being of different lengths1 describe    
different arcs1 the curves of the levers
 when raised are of necessity in error  
to them all4 ,the result of these       
combined faults is that the gatings have
 to be made wider than the stump1 to    
allow a sufficient amount of play1 thus 
introducing a fatal element of          
insecurity in the construction of the   
lock1 since the security is of course   
enhanced in proportion as the gatings   
fit the stump accurately4 ,in the new   
lock1 on the contrary1 the arc ,t1 fig4 
#eh1 in each lever1 can be shaped truly 
to its own proper radius1 independent of
 all the rest of the levers2 and as the 
action of the stump is instantaneous in 
catching the gatings as soon as they are
 all brought simultaneously under it1   
the stump and gatings can be made to fit
 one another with the most perfect      
accuracy1 and without the slightest     
play4  ,on turning the cylinder ,c      
further round1 the bit ,n passes from   

under the levers1 which remain held back
 by the insertion of the stump in the   
gatings2 and just before reaching the   
position shown in fig4 #ei1 the slide   
block ,r has pushed the bit completely  
out of the radial slot1 and the bit     
falls down as shown in fig4 #ei1 and    
drops through a hole into the inside of 
the safe that is locked4 ,at this point 
the back pin of the slide block comes in
 contact with the lower side of the cam 
groove ,o in the stump-bolt1 fig4 #ed2  
and by turning the cylinder ,c onwards  
to the position shown in fig4 #fj1 the  
withdrawal of the bolt ,b is completed1 
bringing the parts into the position    
shown in fig4 #fj4 ,in these drawings   
only one lever ,l is shown2 but there   
are altogether six levers1 as shown in  
the sectional plan1 fig4 #ef4 ,the pin  
,p is fixed in the tail ,d of the main  
bolt1 so as to travel with the bolt2 and
 by this means the springs ,i are       
released from strain1 as shown in fig4  
#fj1 as soon as the bolt is withdrawn4  

,illustration3 fig4 #ei4         99     
99       99       99       99  ,from the
 nicety with which the various parts of 
this lock are constructed1 it is evident
 that the levers must be very accurately
 lifted by the bit of the key in order  
to withdraw the bolt2 and therefore any 
error in the bit1 such as would occur   
with a false bit1 will effectually      
prevent the lock from being opened4     
,this may be illustrated by supposing   
the false bit to be so close an         
imitation as to have five of its steps  
absolutely correct1 and the sixth only  
slightly wrong3 though it is almost     
impossible that such a near approach to 
correctness could be attained in        
practice4 ,the counterfeit bit being    
inserted in the lock1 and the cylinder  
turned round1 all will go on the same as
 with the true bit1 up to the time when 
the false bit reaches the point ,t of   
the levers1 as previously shown with the
 true bit in fig4 #eh4 ,here a change of
 action takes place2 but what is the    

nature of the change the operator has no
 means as yet of ascertaining4 ,in the  
case supposed1 where five of the steps  
in the bit are right1 but the sixth is  
wrong1 the gating of the sixth lever    
does not precisely coincide with the    
others1 nor with the stump ,s2 and the  
consequence is that1 at the critical    
moment when the stump ought to spring   
into the gatings and hold back the      
levers from falling forwards1 it will be
 prevented from entering the gatings1   
owing to the entrance being partly      
blocked up by the one lever1 which      
stands more or less across it4          
,illustration3 fig4 #fj4  ,the fact1    
however1 that the stump cannot enter the
 gatings1 does not become known to the  
operator until the cylinder ,c has been 
turned further round1 so as to bring the
 slide-block pin in contact with the    
lower side of the cam groove ,o in the  
stump-bolt2 and before this point has   
been reached the false bit has already  
passed clear of the levers1 which1 not  

being retained by the stump1 are        
instantly thrown forwards again by their
 springs1 and locked in their original  
position by the stump entering the      
notches4 ,at the same time the false bit
 has dropped into the inside of the safe
 in the same manner as the true bit1 as 
shown in fig4 #fa4  ,illustration3 fig4 
#fa4  ,hence a person putting a false   
bit into one of these locks will not    
only infallibly lose it at the very     
first trial1 but will do so without     
gaining any information as to the nature
 of its inaccuracy2 for as the gatings  
of the levers cannot be seen or felt1   
all that can be told about the action of
 a false bit is1 that it has failed to  
open the lock4 ,in fact1 a counterfeit  
bit passes under the levers1 and through
 the lock1 just like the true bit2 and  
it is only the stoppage afterwards met  
with of the bolt that indicates the     
failure of the false bit1 which is by   
that time gone beyond recovery4         
,whatever amount of labour1 therefore1  

may have been spent on the fabrication  
of a counterfeit bit1 this bit can only 
be tried once1 so that no alteration can
 afterwards be made in it4  ,nothing    
that can be inserted into the radial    
slot of the cylinder ,c through the     
aperture in the front plates can do any 
injury to the lock2 and a charge of     
gunpowder inserted in that way would    
only blow out again at the orifice      
without damaging the lock1 both the     
apertures for the key being merely blind
 holes with parallel sides4         99  
99       99       99       99           
,illustration3 fig4 #fb4  ,illustration3
 fig4 #fc4  ,for the manufacture of the 
bits for the keys of this lock a        
self-acting machine is employed1 in     
which the height and width of the       
several steps in the bit are regulated  
by adjustments of very great accuracy1  
and admitting of an almost endless      
variety of figure for the bits4 ,this   
key-cutting machine is shown in figs4   
#fb to #fd1 and consists of a small     

circular saw ,a running vertically1 of  
the same thickness as each step in the  
bit ,i1 which is brought up to the saw  
by the slide-rest ,b4 ,the bit ,i is    
fixed in the holder ,c1 which rocks upon
 a centre1 so as to give the required   
curvature to the edge of each step in   
the bit when cut by the saw1 as shown in
 the full-size section of the           
bit-holder1 fig4 #fc4 ,the adjustment of
 the depth of cut is effected by the set
 screw ,d upon the slide-rest coming up 
against the eccentric ring ,e upon the  
bed of the slide-rest2 this ring is     
turned round by hand1 and set to sixteen
 different positions by means of the    
catch-pin ,f and the sixteen holes on   
the circumference of the ring1 allowing 
of sixteen different depths of cut4 ,the
 lateral adjustment for the pitch       
between the successive steps of the bit 
is effected by the two bed-screws ,g ,g 
acting on the slide-rest ,b1 having a   
dividing plate on the head1 and such a  
pitch of thread that one turn of the    

screws traverses the slide-rest through 
the exact distance of one step in the   
bit4 ,the occurrence of any play or     
backlash is entirely prevented by having
 the screws placed one at each end of   
the slide-rest2 so that by slacking back
 one screw through one or more turns1   
and then advancing the other through the
 same number of turns1 the slide-rest is
 always held with perfect steadiness    
between them1 filling exactly the space 
between the ends of the two screws4     
,the number of changes admissible in    
this key-cutting machine1 if used for   
making keys for locks having six levers1
 is the number of permutations that     
sixteen terms are capable of when taken 
six together1 which is upwards of       
sixteen millions4 ,some of these changes
 are so slight that too great accuracy  
of workmanship would be required to make
 the locks accordingly2 but of those    
changes that differ from one another so 
far that no lock could be opened by any 
other than its own key1 more remain than

 could be used up by all the locks in   
the world4  ,illustration3 fig4 #fd4    
,the writer may observe that it was the 
study of the circumstances of the great 
gold robbery on the #aeth of ,may1      
#ahee1 by ,agar and his confederates    
7when two of the best lever locks were  
picked1 and gold stolen weighing upwards
 of #bjj lbs41 while in transit on the  
,south-,eastern ,railway from ,london to
 ,paris1 packed in three sealed         
iron-bound boxes1 inclosed in a bullion 
safe1 secured by those locks71 and of   
the various modes of picking locks1     
which led him to turn his attention to  
the achievement of what had been so long
 and perseveringly sought after1 namely1
 an unpickable lock4 ,the principle of a
 detached bit has been previously tried1
 in so far as that locks have been made 
in which the bit of the key was         
deposited in the lock by unscrewing the 
key stem1 and then withdrawn by screwing
 in the stem again4 ,but inasmuch as the
 detached bit1 even though it failed to 

open the lock in the case of a          
counterfeit key1 could always be brought
 back again to the keyhole and removed1 
this admitted of a repetition of        
attempts with successive alterations of 
the one counterfeit key1 without the    
certainty that any warning would be     
given by the lock of such attempts      
having been made4  ,in another still    
more complicated lock with a detached   
bit there were two keyholes1 into one of
 which the bit of the key was put1 and  
the stem being then unscrewed from the  
bit1 was put into the second keyhole and
 turned round so as to close the first  
keyhole over the bit2 a separate handle 
was then turned to work the lock1 six   
separate operations being required for  
either opening or closing the lock4     
,further1 a kind of retainer has been   
attempted by so arranging the lock that1
 if any key was put in but the right    
one1 it was held in the keyhole in such 
a manner that it could never be got out4
 ,in this case1 however1 if the false   

key would not open the lock1 neither    
would it let even the right one do so1  
and it would be necessary to break open 
the door secured by the lock4         99
       99       99       99       99    
,in the new lock here described1 the    
special points that have been aimed at  
are the following3--  ,firstly1 in no   
position of the lock is there any access
 to the works from the outside through  
the keyhole4 ,this access through the   
keyhole is more or less a defect in all 
other principles of lock1 as it admits  
of feeling and manipulating the works   
for the purpose of getting information  
for picking the lock in the absence of  
the right key2 whereas in the new lock  
there is no opening whatever at any     
time1 except the two plain parallel     
recesses into which the key and the bit 
are fitted4 ,from the moment the turning
 of the lock commences both these       
recesses are effectually blocked up3 the
 one for the bit being conveyed bodily  
away from the keyhole1 and its place    

taken by the solid metal of the         
cylinder2 while the other is completely 
filled by the key1 which cannot be      
withdrawn except by turning it back to  
the original position4 ,in consequence  
of this construction no injury can be   
done to the lock by explosion of        
gunpowder in the keyhole1 the only      
openings from the outside being parallel
 at their sides1 and not communicating  
with any portion of the interior of the 
lock2 and the simplicity and solidity of
 construction are such that the         
revolving cylinder is made practically  
air-tight within its bearing4 ,this     
effectually prevents all attempts to    
open the lock by picklocks1 and leaves  
no alternative but the attempt to make a
 sufficiently accurate copy of the true 
key4  ,secondly1 as no clue whatever can
 be obtained from the outside of the    
lock respecting the key required1 the   
attempts upon the lock are thus limited 
to the chance of obtaining a wax        
impression of the true key4 ,the        

difficulty of making a counterfeit key  
sufficiently correct by this means for  
opening one of the best of the previous 
constructions of lock is very great2 but
 in the new lock this difficulty is     
greatly increased by the fact of the    
levers remaining absolutely stationary  
while the stump enters the gatings1 in  
consequence of which the gatings are    
made so close a fit to the stump that an
 exceedingly minute error in the lifting
 of any of the levers is sufficient to  
prevent the lock being opened4 ,this    
extreme delicacy of construction can be 
carried out practically without         
objection in the new lock1 because there
 is no possibility of putting a strain  
from the key upon the stump1 so as to   
cause injury by forcing it at the moment
 of entering the gatings2 for the only  
force acting upon the stump at that time
 is the uniform pressure of its own     
spring4 ,in addition to this source of  
increased safety1 there is the still    
more important circumstance that only a 

single trial can be made of each        
counterfeit bit2 because1 if carried    
forwards far enough to try its effect in
 opening the lock by passing the levers1
 the bit is inevitably lost by falling  
through the lock and inside the door4   
,thus not only is all chance prevented  
of a second trial with the same key1 but
 the bit retained inside the door gives 
warning of the attempt having been made1
 and shows how near the counterfeit key 
has approached to the original4 ,the    
numerous cases that have occurred of    
attempts to open locks by counterfeit   
keys1 such as the remarkable instance   
previously referred to1 show that even  
with the most practised hands it is next
 to impossible to make from a wax       
impression a key that will serve for    
opening a good lock the very first time 
it is tried2 and the striking importance
 is therefore seen of this arrangement  
in the new lock1 which prevents more    
than a single attempt being made with a 
counterfeit4  ,thirdly1 another         

advantage to be named in this lock is   
that the stem alone of the key is       
required to lock it1 but it can only be 
unlocked by the complete key4 ,the stem1
 therefore1 can be left by the principal
 of an establishment for locking up by a
 subordinate2 but the bit1 which is the 
essential part of the key required for  
opening the lock1 need never be used or 
seen by any one but the principal       
himself4 ,as the hole in the external   
door-plate for the stem of the key has a
 notch on one side only to admit the key
 stem1 and the cylinder is prevented    
from making a complete revolution1 the  
stem of the key cannot be withdrawn from
 the lock except when the bolt is shot2 
so that its absence from the keyhole    
serves as a proof that the bolt is shot4
  ,fourthly1 one other advantage in this
 lock is its simplicity and solidity of 
construction4 ,it contains no more parts
 than the simpler forms of lever lock   
having the same number of levers1 and   
the total number of separate pieces in  

the complete lock is only sixteen4 ,the 
principle of security1 therefore1 upon  
which the new lock is constructed1      
avoids entirely the complications and   
the delicate and minute class of work   
rendered necessary in other locks by the
 use of detectors and the other         
auxiliary contrivances employed for     
increasing the difficulty of picking4   
99       99       99       99       99  
,mr4 ,fenby exhibited1 at a             
conversazione of the ,institute of      
,civil ,engineers1 and at the meeting of
 ,mechanical ,engineers1 specimens of   
his adytic lock1 and showed its action  
both with the true key and with         
counterfeit keys2 and he showed by trial
 that the counterfeit failed to open the
 lock1 notwithstanding that by means of 
the permutating cutting machine it had  
been made a much nearer approach to a   
perfect copy than was practicable in the
 best handwork from a wax impression4   
,he also exhibited the key-cutting      
machine employed for cutting the bits2  

and also a set of burglar's tools       
employed for drilling into the door of  
an iron safe sufficiently for breaking  
open or removing the lock1 showing that 
the hold required for giving the cutting
 pressure upon the powerful drill       
employed for the purpose was obtained by
 a steel cross piece inserted into the  
keyhole and turned at right angles1 so  
as to hold across inside the lock2 but  
in the new lock1 as the keyhole had no  
opening into the lock1 and only a slight
 shoulder on one side1 no means were    
afforded for obtaining the required hold
 for the drill4  ,the following are the 
salient points of the discussion that   
followed the reading of his paper3--    
,the ,chairman remarked that the paper  
just read gave a very excellent and     
clear description of the detailed       
working of the new lock1 and he thought 
this construction of lock was a most    
valuable one1 as affording real security
 against all fraudulent attempts4 ,he   
inquired whether there would be any     

possibility of tampering with the lock  
by examining it upon the inside of a    
safe door1 whenever the door might      
happen to be left unlocked4  ,mr4 ,fenby
 replied that there was no means of     
tampering with the lock from the inside 
of the door1 as the two keyholes for    
working the lock were only in the front 
face of the door1 and the lock was all  
closed up on the inside of the door1    
excepting the hole through which the bit
 was allowed to drop out2 but this would
 be useless for the purpose of tampering
 with the lock1 as the bit dropped down 
a tube leading to the bottom of the     
door1 through which no examination of   
the lock could be successfully made4    
,the ,chairman inquired whether there   
was any provision against the bit being 
accidentally locked up inside the safe1 
in which case it appeared the lock could
 not be opened again4  ,mr4 ,fenby      
replied that the owner of the safe must 
of course be careful after unlocking the
 safe to take the bit out before locking

 it again1 otherwise there would be no  
means of opening the lock afterwards    
with that key4 ,as a precaution1        
however1 against any such accident1 each
 lock was provided with three bits1 all 
duplicates1 one of which would be kept  
in the pocket for use1 while the two    
others would be preserved in a place of 
safety for the chance of any such       
contingency4 ,moreover1 in most of the  
safes fitted with these locks1 the tube 
through which the bit dropped had been  
made of such a length as to carry out   
the bit on opening the door1 dropping it
 into a small tin tray outside the safe2
 and by this means the accidental       
locking in of the right bit was rendered
 impossible4 ,one of the advantages of  
the new lock was that the stem of the   
key was not required to be kept         
constantly in the possession of the     
owner1 but it might be left in the lock1
 as the bit alone was the valuable part 
of the key2 and as the bits were of such
 small size and convenient shape1 a     

number of them might readily be kept in 
the pocket by a person having charge of 
a number of safes1 without the          
inconvenience attending a large bunch of
 ordinary keys4 ,in the case of an      
attempt being made to open the lock with
 a counterfeit bit1 the advantages of   
retaining the counterfeit inside the    
safe were not merely that the person    
attempting the lock was deprived of his 
instrument1 while the proprietor        
immediately discovered the attempt upon 
the next occasion of opening the safe2  
but the retention of the counterfeit    
itself afforded the means of judging1 by
 a comparison with the true bit1 whether
 the attempt had been made altogether in
 the dark as to the actual construction 
of the lock1 or whether it was likely   
that some clue regarding the true bit   
had been obtained by means of a wax     
impression or otherwise4 ,in the latter 
case the owner of the safe might think  
it desirable to have the lock taken off1
 and the arrangement of the levers      

altered1 and a new bit made so as to    
baffle any further attempts4  ,mr4 ,w4  
,s4 ,longridge observed that the        
inconvenience that had been alluded to  
with the new lock1 of accidentally      
locking up the bit inside the safe1 was 
no greater than occurred with an        
ordinary safe lock if ever the key was  
accidentally lost2 in either case1      
unless the precaution was taken of      
keeping a duplicate in reserve1 it would
 of course be necessary to have the safe
 broken open4  ,the ,chairman inquired  
how the ideas had been arrived at of    
separating the bit from the key1 and of 
preventing all access to the works      
through the keyhole1 and also of        
retaining the bit inside the door after 
any attempt at unlocking4  ,mr4 ,fenby  
replied that his attention had in the   
first instance been attracted to the    
subject of the picking of locks as a    
mechanical problem1 and he had found    
that there had hitherto been no         
principle in lockmaking which could     

effectually baffle persevering attempts 
at picking4 ,for although there were    
certain complicated constructions of    
locks1 having many points of excellence1
 they had all yielded in time to the    
picking instrument in clever hands2 and 
it must be remembered that any          
individual lock when once constructed   
remained stationary as regarded         
subsequent improvement1 whereas the art 
of picking that lock was continually    
progressing towards success1 with all   
previous constructions of locks1 and it 
was clear therefore that the lock must  
ultimately be defeated4 ,he had been    
further stimulated in the investigation 
of this subject by the occurrence of the
 great gold robbery referred to at page 
#ahh2 and the circumstance which had    
struck him most forcibly in connection  
with that robbery had been that locks of
 the best make hitherto known had       
admitted of seven successive trials     
being made upon them without detection1 
each trial furnishing the information   

for further perfecting the counterfeit  
key1 until the locks were at length     
opened4  ,these considerations had led  
him to the conclusion that two points   
were established and were required to be
 kept in view for the construction of   
any lock that should be really secure   
against fraudulent attempts4 ,the first 
point was that wherever a man could get 
instruments into the lock he could      
ultimately solve any problem laid before
 him by the maker of the lock1 as the   
lock when once made could be tried any  
number of times if an instrument could  
be got into it at all4 ,hence he had    
concluded that it was requisite for all 
access to the interior to be cut off1 so
 as to preclude all possibility of      
getting a pick-lock in2 and this was    
accordingly accomplished by adopting the
 plan of separating the bit from the    
stem of the key4 ,the second point      
established was that it was necessary to
 prevent the possibility of making a    
succession of trials with the same      

counterfeit key2 and it had then struck 
him that1 if the bit of the key were    
arranged to drop inside the safe in     
unlocking1 there would be no means of   
going on gradually improving and        
touching up the counterfeit from the    
results of previous trials1 as the false
 bit would be irrecoverably lost in the 
very first attempt1 without furnishing  
any clue whatever as a guide for        
alteration in a subsequent trial4 ,the  
first lock that he had invented for     
meeting the requirements thus pointed   
out had been made with a solid block    
having a tunnel through it1 but         
involving the same principle of         
retaining the bit of the key and keeping
 the levers inaccessible from the       
outside4 ,subsequently1 however1 he had 
abandoned that construction and produced
 the new lock shown in the drawings1    
having the revolving barrel with radial 
slot4  ,the ,chairman proposed a vote of
 thanks to ,mr4 ,fenby for his paper1   
which was passed4   ,,chapter ,,xiv4    

,,fenby',s ,,patent ,,stop-,,lock4      
,this lock has been designed with a view
 to doing away with several weak points 
in the construction of lever locks4     
,the introduction of the movable stump  
by ,mr4 ,hobbs1 in order to defeat      
picking by the tentative method of      
applying pressure to the bolt1 so as to 
cause binding between the stump and the 
levers1 was a great advance in the art  
of lock-making4  ,the movable stump1 as 
so constructed1 was1 however1 open to   
this objection1 that while sufficiently 
delicate and certain in its action to   
render picking very difficult1 it was at
 the same time1 through the smallness of
 its parts--resulting from the confined 
space available for its action--unsuited
 to withstand any amount of force       
applied to push back the bolt4          
,illustration3 fig4 #fe4  ,in the lock  
under notice the stump s is formed in   
the solid on the shorter arm a of a     
cranked lever or oscillating stop a4    
,this stop a works on the steel pin or  

centre b1 which latter has a bearing in 
both plates of the lock4 ,at the end a  
of the stop a is a recess formed to fit 
the corner d of the bolt-head4 c is a   
stud limiting the range of a in an      
upward direction1 so that when in its   
normal position the stop a may just     
clear the bolt-head1 as shown in figs4  
#fe1 #ff1 and #fg4 ,the tail of the     
bolt1 instead of being in the form      
usually adopted1 is formed of the bar e 
set on edge so as to reach from the back
 to the front plate of the lock1        
completely dividing the lower part1 in  
which the keyhole lies1 from the upper1 
in which the main parts of the works are
 placed4  ,this bar e works between the 
guide pieces g g1 so that in whatever   
position the bolt may be1 the division  
of the lock into two chambers is        
complete4 ,at f is the recess in which  
the key acts to move the bolt4 ,the     
levers l turn upon the pin i formed in  
the solid of the bolt-head4 ,the part of
 each lever on which the key is to act  

passes through a slot or recess in e1   
the parts h and h of the levers being   
struck to the arcs of circles1 having   
their centres coincident with that upon 
which the levers turn at i4  ,as it is  
not possible to lift the levers out of  
this slot in the bar e1 and further1 as 
the levers and bolt move together in a  
longitudinal direction1 the movements   
necessary to locking and unlocking open 
no communication between the upper and  
lower chambers of the lock4  ,the       
springs of the levers are formed out of 
the solid metal of the levers           
themselves1 and are thus not liable to  
that displacement which so often occurs 
with separate springs1 nor to the       
corrosion by oxidation incidental to    
steel springs4 ,they are cut round the  
corner1 and down the front of the lever1
 to gain greater elasticity4  ,in fig4  
#fe the lock is shown with the front    
plate removed1 and the works as they    
stand when unlocked4 ,fig4 #ff is the   
same1 except that the works are shown   

locked1 and the back plate removed      
instead of the front4 ,fig4 #fg shows   
the front view of fig4 #ff4 ,fig4 #fh   
shows the result of any attempt to pick 
the lock by pressure4  ,illustration3   
fig4 #ff4  ,illustration3 fig4 #fg4     
,illustration3 fig4 #fh4  ,the lock     
being locked1 as shown in figs4 #ff and 
#fg1 it will be seen that the stop a    
just clears the angle d of the          
bolt-head4 ,further1 that the gatings r 
of the levers l cannot pass the stump s1
 unless the levers be so lifted as to   
coincide with each other and the stump4 
,the stop a being held up by a very     
light pressure from the lever springs1 a
 small force applied to the stump s is  
sufficient to upset its equilibrium1 and
 bring down its end a upon the bolt-head
 at d1 as shown in fig4 #fh4 ,this      
occurs whenever an attempt is made to   
8feel0 the stump with the levers2 and   
not only does the stop a free the levers
 from all pressure1 and so preserve them
 and the stump from injury1 and the lock

 from being picked1 but it also forms a 
strut for securing the bolt3 in fact1 no
 violence short of that necessary to    
shear the pin b can make the bolt yield4
  ,the drawings show a mortise lock1 but
 the improvements shown are universally 
applicable in the construction of locks 
of all kinds4  ,for the manufacture of  
these and other locks1 and kindred      
articles1 ,messrs4 ,j4 ,b4 ,fenby and   
,co41 engineers of the ,liverpool       
,works1 ,birmingham1 have put up1 from  
the designs of their managing partner1  
,mr4 ,j4 ,beverley ,fenby1 an           
experimental set of machinery1 almost   
entirely self-acting1 and calculated to 
turn out large quantities of the        
component parts of locks and other      
articles with extreme accuracy and      
rapidity4  ,the whole set works on the  
interchangeable system--as already in   
use for military small arms4 ,it is not1
 however1 to be supposed that1 because  
the parts of the locks are              
interchangeable1 one key will open      

several locks--such a source of         
insecurity being guarded against by the 
permutating key-cutting machines        
invented by ,mr4 ,fenby4 ,these machines
 give complete command over the making  
of keys1 whether it be required to make 
a comparatively unlimited number1 all   
differing from each other1 to make a    
number alike1 or to make sets with      
master keys4  ,atmospheric and hydraulic
 pressure also plays an important part  
in shaping many of the parts of the     
locks4   ,,note ,,upon ,,iron ,,safes4  
,at the conclusion of this work upon    
locks it will not be out of place to    
make a few remarks upon the degree of   
real safety that attaches to what are   
commonly called 8safes10 and to point   
out in a common-sense way what are the  
chief dangers that these may incur from 
depredators 7whether burglars or in     
times of public anarchy and violence71  
and what are the main conditions to be  
relied upon for safety--assuming that1  
by one or other of the constructions    

pointed out in the preceding pages1 the 
lock of the safe be such as to be       
practically unpickable1 and that        
carelessness shall not have placed the  
true key in the possession of the thief4
  ,there can be no doubt upon the mind  
of any mechanic or engineer1 thoroughly 
acquainted with practical working in    
metals1 that a good deal of what has    
been brought forward and affirmed1 both 
by safe-makers and by burglars          
themselves 7turned approvers71 as to the
 wonderfully-ingenious devices resorted 
to by the latter1 by which1 if we were  
to believe it all1 nothing in the shape 
of steel or iron can possibly withstand 
ultimately the redoubtable powers of    
these people1 is simply                 
fiction--imaginary ingenuity utterly    
impracticable if tried4 ,such1 for      
example1 is the notion of its being     
possible1 by an ounce or two of         
gunpowder exploded in the interior1 to  
so blow asunder and dislocate the parts 
of a well-made safe-lock that the bolts 

shall then be easily got loose1 or that 
a steel-plated safe which resists the   
drill can be softened 8by the blowpipe40
 ,and just as absurd are some of the    
wonderful pieces of ingenuity by which  
some of the burglars' actual devices are
 supposed to be met and frustrated2 as1 
for example1 one for which we believe a 
patent has been obtained1 consisting in 
filling-in the hollow space between the 
inside and outside plates of the safe   
with cast-iron bullets left loose4      
,these might1 no doubt1 break a         
flat-stemmed drill1 after that had      
pierced the outer plate1 but could have 
no effect whatever upon a round-shanked 
drill1 such as one of the ordinary      
,american spiral1 or teredo-pointed     
drills4  ,that there are some methods of
 violence still untried1 and yet at the 
command of the burglar who dares to risk
 a tolerably loud noise of explosive    
agents1 is well known to skilful        
mechanical engineers1 and for obvious   
reasons it would be unwise that we      

should give any information as to such2 
but the real practical and too-often    
effectual methods of the burglar limit  
themselves almost entirely to the use of
 the succession of steel wedges1        
followed by the powerful steel-pointed  
pinching bar1 or bars1 to the forcing or
 prizing-screw1 and to making more or   
less way for this by cutting out        
beforehand by the pin-drill4  ,a safe1  
to be safe1 must be so circumstanced or 
so constructed1 or both1 that it should 
be able to resist the best efforts that 
can be made by these methods for several
 hours2 perhaps we might say as much as 
thirty to thirty-six hours--viz41 from  
,saturday night to ,monday morning4     
,now we hesitate not to say that the    
unsafeness of 8safes0 arises not from   
any structural difficulty whatever1 but 
almost always from the parsimony and    
ignorance of those who purchase and     
employ them4 ,safes1 like razors1 are   
made to sell1 and if the public demand  
is for cheap safes1 such as we see every

 day advertised in the newspapers1 it   
was sure to have been1 and is1 met by a 
supply of things called safes which are 
utterly unsafe4 ,the great mass of the  
showy green and gold gewgaws that one   
sees in the safe-shop windows1 with     
flaming testimonials as to their fire   
and burglar-proof powers1 are simple    
shams3 a genuine safe could not be made 
at their prices4  ,the very first       
condition to constitute a genuine safe  
is that it shall have an ample mass of  
metal--i4e41 not of cast-iron1 but of   
wrought-iron1 or best of steel1 all     
round it2 and especially that the       
margins of metal all round the door     
shall be of such huge and surplus       
scantling that no amount of wedging1 by 
construction possible1 should be able to
 bend any one side sensibly4 ,the next  
is that the workmanship of every part of
 the safe be first-class3 not that there
 be merely a moulded door with a showy  
lock and a trumpery brass-plate upon it1
 but that every corner and joint of     

plate with plate in sides and back be   
effectually united and jointed in the   
best manner1 and that the fitting of the
 hardened edges of the door shall be    
like those of a valve1 and not even let 
a watch-spring be got in between4 ,if   
these obvious conditions be observed1   
and that the safe itself be properly    
posited in the premises1 it will be     
found1 even with ordinary forms of      
construction as to doors and bolts1 but 
with a really unpickable lock1 a very   
hard nut for the best burglar to crack4 
,illustration3 ,chatwood's ,safes4  ,but
 much more may be effected without any  
serious increase of cost4 ,several forms
 of safes are now made1 the rabbets of  
the doors of which are so formed that it
 is almost a physical impossibility to  
get any wedge1 however thin1 to drive in
 between the door and the frame4 ,this  
is effected in ,chatwood's patent safes 
7of ,bolton and ,manchester71 as figured
 above1 by making the door rabbets in   
cross section curvilinear1 so that even 

if the fit be not so perfect but that   
the edges of a very thin wedge can still
 be inserted1 it yet cannot be          
driven--for1 as it goes forward1 it must
 become curved1 and if soft1 so as thus 
to bend1 the thin steel will not bear   
the severe strain of driving1 but if    
hard1 it breaks off into short bits     
close to the entrance4 ,in addition to  
this ,chatwood's 7and we believe other  
makers'7 safes have bolts so            
constructed1 as seen in the figure1 that
 they hook or lock into the bolt        
recesses in the frame in such a manner  
as to hold the opposite sides of the    
frame together1 so that1 independent of 
its own proper stiffness1 it cannot be  
bent anywhere1 unless by tearing asunder
 the end on the iron bar constituting   
each cross-bolt4 ,the bolts1 in fact1   
not only secure the door 7as in         
ordinary7 from opening1 but secure the  
door and frame together4 ,with such a   
safe1 if the owner will only provide a  
proper position for it in his premises1 

he may rest pretty easy in mind4  ,safes
 are very commonly stood upon a wooden  
floor1 or made to form part of a        
wood-framed bookcase1 or press1 or stand
 in a recess4 ,often they are comeatable
 all round1 and even underneath1 with   
nought but an inch board below them1 and
 almost always they are left with the   
front door freely and fully exposed1 and
 with ample and convenient room left all
 round4 ,this for two or three workmen  
to manipulate the safe as they may4     
,now the only real conditions of safety 
are that the iron safe should be bedded 
into brickwork set in ,portland cement  
and sand2 or1 what is much better1 in   
hard granite or gritstone masonry1      
bedded in like manner4 ,without this be 
done1 a fire-proof safe is simply a     
delusion2 constructed how it may be1 it 
is only a crucible of more or less      
badly-conducting power1 in which1 after 
a time longer or shorter1 deeds1        
bank-notes1 documents1 c41 will be      
calcined1 and coin or jewellery melted1 

and gems flawed and destroyed4 ,we say  
this in the full face of the delusive   
so-called 8fiery ordeals0 to which many 
of the so-called double-cased fire-proof
 safes are alleged to have been for     
hours exposed4 ,the safe should always  
be embedded in masonry1 and rest upon   
that in such a way that it cannot get   
undermined by either fire or burglars4  
,whenever the premises admit of it1 the 
door of the safe itself should be set   
back #aj or #ab inches from the face of 
the wall in which it is embedded1 and an
 outer door1 flush with the face of the 
wall1 should be provided of iron1 with a
 good lock and multiple bolts4 ,the door
 of the safe should open to the right2  
and if so1 the outer door should open to
 the left2 and neither should open more 
than square to their position when shut4
 ,no one but a practical workman or     
engineer can have an adequate notion of 
the extent to which any mechanical      
operation upon the door of a safe thus  
circumstanced is hampered by its being  

set back into the wall1 and with an     
outer door that even when open1 cuts off
 all ready manual access to the inner   
door from one side4  ,when premises are 
constructed1 as they should be for all  
banks and bullion merchants1 jewellers1 
c41 having special regard to a safe as  
an indisputably secure depository1 then 
the safe should be completely iron or   
steel cased1 and embedded in hard stone 
masonry 7we shall not here go into      
additional special precautions against  
the remoter effects of fire71 covered in
 with a strong fire-brick arch1 and with
 nothing but the solid ground below4    
,the door of the safe should only be    
approachable through an iron or         
stone-lined passage1 just the size of   
the safe-door1 and no more4 ,this should
 be some feet in length1 and have an    
outer double-cased steel door1 or       
perhaps that and an intermediate iron   
falling-door or portcullis1 between the 
outer door and the safe-door4 ,with a   
safe-door so circumstanced1 even        

supposing both these outer doors forced 
and open1 it is almost impracticable for
 even a single workman1 however agile or
 adroit1 to perform any mechanical      
operation whatever upon the door1 least 
of all upon its surrounding rabbates4   
,these are so close to the solid granite
 walls1 starting out at right angles    
from the rabbate all round1 that he has 
no room to do anything2 and to get a    
prizing-bar at the door-rabbate1 or even
 to get a second man to assist the first
 in any way1 is impossible1 simply for  
want of room4  ,the whole of the doors  
and all the surfaces of such passage    
should be painted a dull1 lustreless    
black4 ,no one who has not tried it1 has
 any idea of the difficulty of          
illuminating such a black passage1 by   
even several candles1 sufficiently to   
perform any delicate mechanical         
operation2 and good light is essential  
to the safe-breaker4  ,in banks there is
 no better plan than has been ere now   
adopted of making the iron safe a great 

cube1 with the door at one side1 placing
 the whole safe with its bottom resting 
upon the stem or plunger of an hydraulic
 press1 the cylinder of which is fixed  
in the bottom of the pit in the solid   
earth1 of a size capable of enabling the
 whole safe to be bodily lowered down   
into the cavity at the end of the day's 
work1 and pumped up again out of its    
hiding-place the next morning4 ,the     
lever of the hydraulic pump is taken    
away1 and the socket into which it fits 
is plugged1 and the plug locked into its
 place1 and then the pump--situated in a
 recess in solid masonry--is itself     
locked up4 ,the top of the safe itself1 
when it has been lowered to the bottom  
of its chamber1 stands #aj or #ab inches
 below the floor-level of the stone     
floor1 and a pair of iron doors is then 
closed over it and locked down4  ,a safe
 executed in this way1 though requiring 
a considerable expenditure at first1 if 
well done1 might bid defiance to        
anything almost1 even unlimited         

gunpowder1 for some days4 ,the only     
addition of safety that almost could be 
conceived would be that adopted at the  
bullion vaults of the ,bank of ,france  
in ,paris1 where these1 situated in     
casemates two stories under ground1 are 
only approachable by one narrow1 winding
 staircase1 which can be itself1 in case
 of emergency1 rapidly rendered useless1
 and the cylindrical well in which it is
 placed filled up with about #cj feet in
 depth of water1 which cannot be pumped 
out until a continuous supply be shut   
off by distant means only known to one  
or two trusted employs4  ,since this    
revision has been in type the great     
8safes' contest0 or wager of battle     
between the rival safes of ,mr4 ,herring
 of ,new ,york1 and ,mr4 ,chatwood of   
,bolton1 for #fjj a side1 has come off1 
at the ,international ,exhibition1      
,paris1 ,mr4 ,r4 ,mallet and ,mr4       
,robert ,f4 ,fairlie1 ,c4,e41 being the 
representatives of the ,english         
interests upon the occasion4 ,the       

result1 which1 owing to the conduct of  
some of the parties concerned1 assumed  
an unpleasant and incomplete form1 may  
be found detailed fully in a pamphlet   
published by ,tinsley ,brothers1        
,london4 ,it is referred to here        
because1 although no decision of the    
wager made could be come to1 the facts  
ascertained are of great interest and   
importance as respects the proper       
construction of safes4 ,they show       
conclusively that an effectively        
constructed door and jambs is really the
 one thing needful to absolute security1
 provided the safe itself be built up1  
as we have urged1 into masonry4  ,they  
also show that there are good grounds   
for doubting that the ,american         
7,herring's7 8safe within safe0         
construction1 with a thick mass of      
so-called fire-proofing powdery         
composition between them1 is at all as  
protective against mere violence and the
 persevering use of wedges1 as          
,chatwood's simpler but far more        

effective construction1 especially of   
his door and jambs4 ,if one of the      
latter safes1 wholly of steel plating1  
be fairly embedded into masonry1 and    
another outside flush door of his       
construction1 with curved rabbates and  
hooking locking bolts1 be supplied to   
the masonry ope itself1 it is scarcely  
an exaggeration to call such a safe     
8,invincible10 so far as anything that  
burglars1 in any civilised place in     
,europe at least1 can effect4           
,,index4     ,adytic lock1 #agf2        
machine for manufacturing the keys of   
the1 #ahe2     number of changes in the 
lock1 #ahh2     advantages of1 #ahi2    
discussion on its value1 #aib4          
,ainger on the ,bramah lock1 #aaa4      
,ainger's lock1 #fa4    ,alarum lock1   
#dj4    ,american locks1 #hb2           
,stansbury's lock1 #hc2     ,yale's     
lock1 #hc2     ,dr4 ,andrews's lock1    
#hd2     ,day and ,newell's locks1 #hf2 
their ,parautoptic lock1 #hi2           
,hobbs's ,protector lock1 #ii4          

,ancient locks1 #h4    ,andrews's lock1 
#hd2     snail wheel lock1 #he4         
,appendix1 #agc4    ,aubin's lock       
trophy1 #aff2     locks forming it      
described1 #afh4     ,barron's tumbler  
lock1 #di2     ,bramah on1 #fh4         
,bird's tumbler lock1 #eb4    ,bramah on
 ,barron's tumbler lock1 #fh2     on the
 defects of the tumbler lock1 #fh2      
on the defects of the warded lock1 #ff4 
,bramah lock1 #gj2     cylinder lock1   
#gc2     number of changes in the       
,bramah lock1 #ha2     picked by ,mr4   
,hobbs1 #aba2     report of the         
arbitrators1 #abc1 #abd2     a          
description of the lock picked1 #abe2   
letters from ,messrs4 ,bramah           
questioning the fairness of the trial1  
#abf2     method of picking1 #aaj2      
method employed by ,mr4 ,hobbs1 #abi2   
,ainger on the ,bramah lock1 #aaj2      
,farey on the ,bramah lock1 #aac2       
improvements made since #ahea1 #aca4    
,brown's letter lock1 #bc2     picked by
 ,mr4 ,hobbs1 #aci4    ,bullion vaults  

of the ,bank of ,france1 #bjf4          
,chatwood's safes described1 #bjc4      
,chinese locks1 #aga4    ,chubb on      
,davies's lock1 #aab2     on lock       
picking1 #acb4    ,chubb's lock1 #ec2   
described1 #ed1 #ef2     key of1 #eg2   
attempt to pick1 #eh2     experiments   
on1 #ei2     number of changes in the   
lock1 #ee2     the detector lock picked 
by ,mr4 ,hobbs1 #aae2     value of the  
detector questioned1 #aag2              
improvements1 #aba2     ,mr4 ,hodge on  
the ,chubb lock1 #aad2     ,chubb's new 
locks1 #adg2     bank locks1 #adi4      
,clockwork1 application of1 to locks1   
#ci4    ,closet-lock1 #ag4              
,commercial importance of locks1 #b4    
,contrivances for adding to the security
 of locks1 #ce4    ,cut locks1 #ah4     
,davies's lock1 ,captain ,o',brien on   
#aab2     ,mr4 ,chubb on1 #aab4         
,davis's lock1 #fj4    ,day and         
,newell's lock1 #hf2     ,parautoptic   
lock1 #hi et seq4    ,dead-lock1 #ag4   
,denison's large lock1 #adb2     small  

ditto1 #adf4    ,dial locks1 #bc2       
method of picking1 #ach4    ,duhamel du 
,monceau's ,art du ,serrurier1 #d4      
,egyptian door-fastenings1 #ac4         
,egyptian pin-lock1 #ad2     method of  
picking1 #aci4    ,escutcheon1 uses of  
the1 explained1 #cg4    ,exhibition of  
#ahea1 effects of the1 in improving     
,english locks1 #adj2     ,jury ,report 
on locks1 #aca2     observations on the 
,report1 #acc4     ,farey on the ,bramah
 lock1 #aac4    ,fenby on warded locks1 
#agc2     on tumbler locks1 #agd4       
,fenby's adytic lock1 #agf2     machine 
for making the keys of1 #ahe2     number
 of changes in the1 #ahh2     advantages
 of1 #ahi2     discussion on the value  
of the lock1 #aib2     stop-lock1 #aif2 
machines for the manufacture of the     
locks1 #bjj4    ,fons1 ,mr4 de la1 his  
improvement in locks1 #adh4    ,french  
locks1 ancient1 #cb4    ,friend's secret
 lock1 #ci4     ,greek locks1 #i4       
,hobbs on ,english locks made before    
#ahea1 #aae2     he picks a ,chubb lock1

 #aaf2     a ,bramah lock picked by ,mr4
 ,hobbs1 #abb2     his mode of picking  
the ,bramah lock described1 #abi2       
,mr4 ,brown's letter-lock picked by him1
 #aci4    ,hobbs's protector lock1 #ii4 
,hodge on the ,chubb lock1 #aad4        
,iron-rim lock1 #ag4    ,iron safes1    
value of1 #bja2     the best position   
for a safe1 #bjd2     chamber for       
jewellers' safes described1 #bje2       
arrangement of bank safes1 #bje2        
,chatwood's safes1 #bjc4     ,kemp's    
union lock1 #ha4    ,keys1 master1 #ca2 
skeleton1 #cj2     ,mackinnon's key1    
#fb2     ,machin's web key1 #aed4       
,knob lock1 #ag4     ,lacedmonian lock1 
#aa4    ,left-hand lock1 #ag4    ,letter
 locks1 #bb2     method of picking1     
#ach4    ,lever locks1 #dc4             
,literature of lock-making1 #d2     list
 of references to the 8,transactions of 
the ,society of ,arts0     relating to  
lock-making1 #aff4    ,lock             
classification1 #ag4    ,lock           
controversy1 #ajb2     previous to the  

,great ,exhibition1 #ajc2     ,mr4      
,chubb on ,davies's lock1 #aab2         
,captain ,o',brien on ,davies's and     
other locks1 #aab2     ,mr4 ,farey on   
the ,bramah lock1 #aac2     ,mr4 ,hodge 
on locks1 #aad2     lock controversy    
during and since the ,great ,exhibition1
 #aae2     ,mr4 ,hobbs on ,english      
locks1 #aae2     he picks the ,chubb    
lock1 #aaf2     the ,bramah lock picked 
by him1 #aba2     statements of ,messrs4
 ,bramah1 #abe2     attempt of ,messrs4 
,garbutt to pick the parautoptic lock1  
#acd4    ,lock manufacture at           
,wolverhampton1 state of1 described1    
#aed4    ,lock-picking1 distinction     
between 8picking0 and 8ringing the      
changes0   on a lock1 #acf2             
tentative process of picking1 #aaj2     
method of picking letter and dial locks1
 #ach2     mode of picking the ,egyptian
 lock1 #aci2     method of picking      
tumbler locks1 #aah2     method of      
picking the ,yale lock1 #adj2     ,mr4  
,chubb on lock-picking1 #acb2           

contrivances to prevent the picking of  
locks1 #aje4    ,lock trophy1 ,aubin's1 
#aff2     locks composing the1          
described1 #afh4    ,lock and key1      
improved1 #agf4    ,locks1 ,english     
patents for1 #afd2     ,jury ,report1   
,exhibition of #ahea1 on1 #aca2         
observations on the ,report1 #acc2      
effects of the ,exhibition of #ahea in  
improving ,english locks1 #adj2     use 
of machinery in the manufacture of1     
#afc1 #bjj4    ,locks1 c41 invented by  
the ,marquis of ,worcester1 #ce4        
,locks and keys1 literature of1 #d2     
list of references in the 8,transactions
 of the ,society of ,arts0     relating 
to1 #aff4    ,louis ,,xvi41 his fondness
 for lock-making1 #bf1 #ce4             
,machin's web key1 #fa4    ,mackinnon's 
key1 #fb4    ,manufacture of locks and  
keys at ,wolverhampton1 state of the1   
#aed4    ,marshall's secret escutcheon1 
#cg4    ,master keys1 #ca4    ,meighan's
 alarum lock1 #dj4    ,mitchell and     
,lawton's tumbler lock1 #eb4    ,mortise

 locks1 #ag1 #ah4    ,multiple-bolt     
locks1 #da1     ,nettlefold's lock1 #fj4
    ,newell's parautoptic lock1 #hi4    
,o',brien1 ,captain1 on ,davies's lock1 
#aab4    ,owen's experiments on ,chubb  
and ,bramah locks1 #ei4     ,parautoptic
 lock1 #hi2     key1 #ia2     ,austrian 
,report on1 #ic2     ,english patent    
for1 #ih2     attempts to pick the1 in  
,america1 #ajf2     ,report of the      
,american ,institute on the lock1 #ajg2 
latest challenge issued by ,messrs4 ,day
 and ,newell1 #ajh2     ,mr4 ,garbutt's 
attempt to pick the1 #acd2     failure  
of the attempt1 #ace4    ,parnell's     
defiance lock1 #ada4    ,parson's lock1 
#fa4    ,patents1 ,english1 for locks1  
#afd4    ,pin-lock of ,egypt1 #ad4      
,puzzle-lock1 #ai4     ,regnier's puzzle
 locks1 #ba4    ,right-hand lock1 #ag4  
,ring lock1 #ag4    ,roman locks1 #aj4  
,rowntree's tumbler lock1 #ej4          
,russell's screw-lock for casks1 #ch4   
,russian locks1 #aga4    ,rutherford's  
lock1 #ci4    ,ruxton's detector for    

tumbler locks1 #ec4     ,safes1 value of
 iron1 #bja2     ,chatwood's1 #bjc2     
see also ,iron ,safes4    ,saxby's prize
 lock1 #aeb2     picked by ,mr4 ,hobbs1 
#aec4    ,screw locks1 #ch4    ,skeleton
 keys1 #cj4    ,society of ,arts' prize 
lock1 #cj4    ,somerford's lock1 #fj4   
,spring-stock lock1 #ag4    ,stansbury's
 lock1 #hc4    ,stop lock1 ,fenby's1    
#aif4    ,straight locks1 #ah4          
,tentative process of lock-picking1     
#aaj4    ,three-bolt lock1 #ag4         
,tumbler locks1 #dc2     lock described 
by ,m4 de ,raumur1 #df2     modern      
tumbler lock1 #eb2     introduction of  
the detector1 #ec2     ,chubb's lock1   
#ec1 #ef2     key of1 #eg2              
advantages and defects of tumbler locks1
 #fc2     ,hobbs's method of adjustment1
 #fc4    ,tumbler locks1 ,mr4 ,fenby on1
 #agd2     method of picking1 #aah2     
double action1 #di4    ,two-bolt lock1  
#ag4     ,ward locks1 #ah4    ,warded   
locks1 #bg2     action of the key on the
 wards1 #bh2     insecurity of1 #bi2    

warded locks of the last century1 #ca2  
insecurity of1 illustrated by ,mr4      
,chubb1 #cd2     ,bramah on the defects 
of1 #ff2     ,mr4 ,fenby on1 #agc4      
,wheel locks1 #ah4    ,wheel and pinion1
 application of1 to locks1 #ci4         
,williams's lock1 #fb4                  
,wolverhampton1 account of the state of 
the lock and key manufacture   at1 #aed4
    ,worcester1 inventions of the       
,marquis of1 relating to lock-making1   
#ce4     ,yale's lock1 #hc2     method  
of picking1 #adj4    ,yale's cylinder   
lock1 #aeb4   ,,printed ,,by ,,virtue   
,,and ,,co41 ,,city ,,road1 ,,london4   
99      99      99      99      99      
99     ,transcriber's note3             
,inconsistent spelling and hyphenation  
have not been standardised4    ,the     
calculations in the text regarding the  
number of combinations and              
permutations have been transcribed      
without further comment1 even when      
they might be open to discussion4       
,the reference letters and numbers given

 in the descriptions of   illustrations 
are not always present in these         
illustrations1 but they   may be present
 in other illustrations of the same     
object4    ,page #cc1 ,s ,s1 ,o ,o1 ,z  
,z1 are ornaments fastened on at b c d3 
this   does not appear to be in         
accordance with the illustrations4      
,page #aec1 footnote #aa3 these figures 
are not present in this book4    ,page  
#afd3 8,as no complete list 4443 the    
closing quote mark is missing4    ,page 
#afd ff1 table1 entry #aghd3 the date   
column was blank in the   source        
document4     ,changes made             
,footnotes have been moved to under the 
paragraph in which they were            
referenced4    ,page #i3 closing quote  
mark inserted after curious knot4       
,page #de3 receptacles at ,c d changed  
to receptacles at c d4    ,page #dh3    
fig4 #bc was printed upside-down in the 
source document4    ,page #ea3 the      
notches f or g in the bolt changed to   
the notches   s or g in the bolt1 cf4   

fig4 #bf4    ,page #eg3 the notches n n 
changed to the notches n n4    ,page    
#gg3 shewn at a a in fig4 #cg changed to
 shewn at a a in   fig4 #cg2 #c1 #b1 #c 
changed to #c1 #b1 #c4    ,page #hi3 ,t 
the third changed to ,t the third cf4   
illustration4    ,page #ajj3 piece of   
metal h p changed to piece of metal h h 
cf4   illustration4    ,page #ajd3 ged  
changed to get4