,,american      ,horological ,journal4  
,,vol4 ,i4      ,,new ,,york1 ,,july1   
#ahfi4      ,,no4 #a4                   
,,contents4        ,,astronomy ,,in     
,,its ,,relations ,,to ,,horology1      
#e      ,,watch ,,and ,,chronometer     
,,jewelling1                  #aa       
,,hints ,,on ,,clocks ,,and ,,clock     
,,making1                 #ae           
,,notices ,,of ,,new ,,tools1           
#ag      ,,greenwich ,,observatory1     
#ag      ,,pinions1                     
#bj      ,,new ,,three-,,pin            
,,escapement1                           
#bc      ,,english ,,opinion ,,of       
,,american ,,watch ,,manufacture1    #bc
      ,,correspondence1                 
#bd      ,,eclipse ,,of ,,the ,,sun1    
#be      ,,diamond ,,cutting1           
#be      ,,alloys ,,of ,,aluminum ,,with
 ,,copper1                   #be        
,,equation ,,of ,,time ,,table1         
#bh     ,address all communications for 
,,horological ,,journal to ,g4 ,b4      
,,miller1 ,p4 ,o4 ,box #fgae1 ,new ,york

 ,city4 ,publication ,office #bbi       
,broadway4          ,astronomy in its   
,relations to ,horology4    ,,number    
,,one4      ,however accurate an        
instrument for the mensuration of time  
may be1  it would be of little use for  
close observation unless we have some   
standard by which to test its           
performance4 ,we look to ,astronomy to  
furnish us with this desideratum1 nor do
 we look in vain4 ,the mean  sidereal   
day1 measured by the time elapsed       
between any two consecutive  transits of
 any star at the same meridian1 and the 
mean sidereal  year--which is the time  
included between two consecutive returns
 of the  sun to the same star--are      
immutable units with which all great    
periods  of time are compared2 the      
oscillations of an isochronous pendulum 
affording us a means of correctly       
dividing the intermediate space into    
hours and days4    ,we must premise that
 the whole theory of taking time by     
sidereal  observations is based on      

angular motion1 the mensuration of one  
of  the angles of motion giving a       
measurement of space1 so that to say    
space1 or distance1 is equivalent to    
saying time4 ,from noon of one  day to  
noon of another is the whole problem to 
be solved by correct  division4 ,the    
astronomical day begins at noon1 but in 
civil law the  day is dated from        
midnight4 ,so in the year the           
astronomical day is  dated ,december    
#ca1 while in common reckoning the #ast 
of ,january is the  initial point4 ,this
 day is divided into twenty-four hours1 
counted in  ,england1 ,america1 and the 
most of the ,continental nations of     
,europe1 by  twelve and twelve4 ,the    
,french astronomers1 however1 adopted   
the decimal  system1 for ease in the    
computation4 ,thus they divided the day 
into  ten hours1 the hour into one      
hundred minutes1 and the minute into one
  hundred seconds4 ,this plan was in    
conformity with the ,french system  of  
decimal weights and measures4 ,again1 in

 ,italy1 the day was divided  into      
twenty-four hours1 but counting from one
 to twenty-four o'clock4  ,the ,french  
system presents some features well      
worthy of adoption1 as it  gives results
 so much more easy in computation--a    
facility unattainable  in the common    
division2 yet it did not come into      
general use in other  countries1 and    
although some ,french astronomers still 
hold to the  system1 it is gradually    
dying out4    ,at one time during the   
,revolution in ,france a clock in the   
gardens of  the ,tuileries was regulated
 to show time by the decimal system4    
,for the ,horologist the mean length of 
the day is sufficient to show the  rate 
of his instrument for that particular   
day1 but the astronomical  and civil    
division requires a much longer period  
of observation4 ,this  is obtained by   
the position of the mean annual         
equinoxes or solstices1  and is         
estimated from the winter solstice1 the 
middle of the long  annual night under  

the ,north ,pole2 and the period between
 this solstice  and its return is a     
natural cycle1 peculiarly suited for a  
standard of  measurement4    ,even with 
such a standard as the civil year of    
#cfe;d4 #e;h4 #dhm4 #di4gs41  the       
incommensurability that exists between  
the length of the day and  the real     
place of the sun makes it very difficult
 to adjust the ratio  of both in whole  
numbers4 ,were we to return to the point
 in the earth's  orbit in exactly #cfe  
days1 we would have precisely the same  
number  of days in each year1 and the   
sun would be at the same point on the   
ecliptic at the same second at the      
beginning and end of the year4 ,there   
is1 however1 a fraction of a day1 so    
that a solar year and civil are  not of 
equal duration4    ,it is thus we have  
our bissextile year1 from the fact that 
the  inequality amounts to nearly a     
quarter of a day1 so that in four years 
we have a whole day's gain2 but not     
exactly1 because a fraction still       

remains to be accounted for4 ,now1 if we
 should suppress the one day  of        
leap-year once at the end of each three 
out of four centuries1 the  civil would 
be within a very small fraction equal to
 the solar year1  as given by           
observation2 this small fraction would  
be almost entirely  eliminated1 provided
 we suppressed the bissextile at the end
 of every  four thousand years4 ,were   
this fraction neglected1 the beginning  
of the  new civil year would precede the
 tropical by just that much1 so that in 
the course of #aejg years the whole     
day's difference would obtain4    ,the  
,egyptian year was dated from the       
heliacal rising of the star  ,sirius2 it
 contained only #cfe days4 ,by easy     
computation it can be  shown that in    
every #adfa years a whole year was lost2
 this cycle was  called the ,sothaic    
period1 in which the heliacal rising of 
,sirius  passed through the whole year  
and took place again on the same day4   
,the commencement of that cycle took    

place #acbb years before ,christ4  ,the 
year by the ,roman calendar was dated by
 ,julius ,csar the #ast of  ,january1   
that being the day of the new moon      
immediately following the  winter       
solstice in the #gjgth year of ,rome4   
,christ's nativity is dated  on the     
#beth of ,december1 in ,csar's #deth    
year1 and the #dfth year of the  ,julian
 calendar is assumed to be the #ast year
 of our era4 ,the preceding  year is    
designated by chronologists the #ast    
year before ,christ1 the  dates thence  
running backward the same as they run   
forward subsequent  to that period4     
,astronomically1 that year is registered
 #j2 the astronomical year begins  at   
noon on the #cast of ,december1 and the 
date of any observation  expresses the  
number of days and hours which have     
actually elapsed  since that time1 the  
#cast of ,december--,year #j4    ,the   
year is divided into months by old and  
almost universal consent1  but the      
period of seven days is by far the most 

permanent division  of a rotation of the
 earth around the sun4 ,it was the      
division long  before the historic      
period4 ,the ,brahmins in ,india used it
 with the same  denominations as at the 
present day the ,jews1 ,arabs1          
,egyptians1 and  ,assyrians4 8,it has   
survived the fall of empires1 and has   
existed among  all successive           
generations1 a proof of their common    
origin40    ,nothing can be more        
interesting in the study of astronomy   
than its  chronological value4 ,la      
,place says3 8,whole nations have been  
swept  from the earth1 with their       
languages1 arts1 and sciences1 leaving  
but  confused masses of ruins to mark   
the place where mighty cities stood2    
their history1 with but the exception of
 a few doubtful traditions1 has         
perished2 but the perfection of their   
astronomical observations marks  their  
high antiquity1 fixes the periods of    
their existence1 and proves  that even  
at that early time they must have made  

considerable progress  in science40     
,the earth revolving around the sun in  
an ellipse1 the position of the  major  
axis of the orbit would indicate        
something in regard to eras in          
astronomy extending not only beyond the 
historical period1 but so far  back in  
the past that imagination is almost at  
fault4 ,the position of  the major axis 
of the orbit depends on the direct      
motion of the perigee  and the          
precession of the equinoxes conjointly1 
the annual motions  respectively being  
#aa4h and #ej4a1 the two combined       
motions being  #fa4i annually4 ,a       
tropical revolution is made in #bji4hd  
years4 ,this  being a constant quantity1
 we may ascertain when the line of the  
major  axis coincided with the line of  
the equinoxes4 ,this occurrence took    
place about #d1jjj or #d1jij years      
before the year #j4 ,in the year #f1dhc 
the major axis will again coincide with 
the line of the equinoxes1  but then the
 solar perigee will coincide with the   

vernal equinox4 ,so1  it will be seen   
that the period of revolution is #bj1iff
 years4 ,but in  the progress of this   
revolution there must have been a time  
when the  major axis was perpendicular  
to the line of the equinoxes4 ,a simple 
calculation will show that the eventful 
year was #abej2 and so important  is    
this event considered1 that ,la ,place1 
the immortal author of the  ,mchanique  
,cleste1 proposed to make the vernal    
equinox of this year  the initial day of
 the year #a of our era4 ,again1 at the 
solstices the  sun is at the greatest   
distance from the equator2 consequently 
the  declination of the sun is equal to 
the obliquity of the ecliptic4  ,the    
length of a shadow cast at noonday from 
the stile of an ordinary  sun-dial would
 accurately determine the precise time  
on which this  position occurs4         
,though wanting in accuracy1 such a     
measurement is of interest1 from the    
fact that there are recorded            
observations of this kind that were     

taken  in the city of ,layang1 in       
,china1 #aajj years before our present  
era is  dated4 ,this observation gives  
the zenith distance of the sun at the   
moment of the observation4 ,half the sum
 of the zenith distances gives  the     
latitude1 and half their difference     
gives the obliquity of the  ecliptic at 
the period4 ,now the law of the         
variation of the ecliptic  is well      
known1 and modern computation has       
verified both the moment  of taking the 
observation and the latitude of the     
place4 ,eclipses  were the foundation of
 the whole of ,chinese chronology1 and  
recorded  observations prove the        
civilization of that strange race for   
#dgjj years4    ,horology1 with         
astronomy1 was not neglected even as    
early as #cajb years  before ,christ1 as
 the following will show4    ,the cycles
 of ,jupiter and ,saturn are very       
unequal1 the latter being a  period of  
#iah years2 the mean motion of the two  
planets was determined  by the ,indians 

in that part of the respective orbits   
where ,saturn's  motion was the slowest 
and ,jupiter's the most rapid4 ,this    
observed  event must have been #cajb    
years before1 and #adia after the year  
#j2 but  the record shows that the      
observation was taken before the        
last-named  date4    ,since both solar  
and sidereal time is estimated from the 
passage of  the sun and the equinoctial 
point across the meridian of the place  
of  observation1 the time will vary in  
different places by as much as the      
passage precedes each4 ,it being obvious
 that when the sun is in the  meridian  
at any one place1 it is midnight at a   
point on the earth's  surface           
diametrically opposite2 so an           
observation taken at different  places  
at the same moment of absolute time1    
will be recorded as having  happened at 
different times4 ,therefore when a      
comparison of these  different          
observations is to be made1 it becomes  
necessary to reduce  them by computation

 to what the result would have been had 
they been  taken under the same meridian
 at the same moment of absolute time4   
,sir  ,john ,herschel proposed to employ
 mean equinoctial time1 which is the    
same for all the world4 ,it is the time 
elapsed from the moment the  mean sun   
enters the mean vernal equinox1 and is  
reckoned in mean solar  days and parts  
of days4 ,this difference in time is    
really the angular  motion of the earth1
 and by measuring it the longitude of   
any place on  the surface of the earth  
can be determined1 provided we have a   
standard  point of departure1 and an    
instrument capable of accurately        
dividing  the time into small quantities
 during its transit from the meridian on
  which it was rated4    ,as will be    
hereafter shown1 the axis of the earth's
 rotation is  invariable4 ,were the     
position of the major axis of the       
earth's orbit  as immutable1 an         
observation of any star on the meridian 
taken at  any place would always be the 

same4 ,again1 the form of the earth has 
an important effect2 the equatorial     
diameter exceeds the polar1 thus  giving
 a large excess of matter at the        
equator4 ,now the attraction of  an     
external body not only draws another to 
it in its whole mass1 but1  as the force
 of attraction is inversely as the      
square of the distance1  it follows that
 the attracted body would be revolved on
 its own centre  of gravity until its   
major diameter was in a straight line   
with the  attracting body4    ,the sun  
and moon are both attracting bodies for 
the earth2 the plane  of the equator is 
at an angle to the plane of the ecliptic
 of #bc #bg  #cd4fi1 and the plane of   
the moon's orbit is inclined to it #e #h
  #dg4i ,now from the oblate form of the
 earth1 the sun and moon1 acting        
obliquely and unequally1 urge the plane 
of the equator from its own  position   
from east to west1 thus changing the    
equinoctial points to the  extent of    
#ej4da annually4    ,this action1 were  

it not compensated by another force1    
would in time  alter the angle of the   
ecliptic until the equatorial plane and 
the  ecliptic coincided4 ,there are few 
but have seen the philosophical toy     
called the ,gyrascope4 ,this toy1 on a  
miniature scale1 gives a fine           
illustration of the force brought in to 
correct the combined action of  the sun 
and moon on the obliquity of the        
equator4 ,the rotation of the  earth is 
held in its own plane by its own        
revolution1 the same as the  gyrascope  
seems to overcome the laws of           
gravitation by its force of  revolution4
    ,but not only do the sun and moon   
disturb the plane of the ecliptic1  but 
the action of other planets on the earth
 and sun is to be taken  into account4  
,a very slow variation in the position  
of the plane of the  ecliptic1 in       
relation to the plane of the equator1 is
 observed from  these influences4 ,it   
must be remembered that a very slight   
deviation  in the angle can and would be

 detected by observation with modern    
instruments4 ,we do find that this      
attraction affects the inclination of   
the ecliptic to the equator of #j4ca    
annually4    ,this motion is entirely   
independent of the form of the earth4   
,now1  if we assume that the sun and    
moon give the equinoctial points a      
retrograde motion on the ecliptic1 we   
must deduct the influence of the        
planets4 ,we may then calculate the mean
 disturbance by subtracting  the latter 
from the former--the difference is      
settled by both theory  and observation 
to be #ej4a annually4 ,this motion of   
the equinoxes  is called the precession 
of the equinoxes4 ,its consideration    
forms a  very important element in the  
estimation of time1 as the position of  
the various fixed stars1 though so very 
distant1 are all affected in  longitude 
by this quantity of #ej4a--;being an    
increase of longitude4  ,therefore1 if  
we were to calculate the position of any
 given star in  order to get a transit  

for mean time1 or true time1 we must    
take this  quantity into consideration4 
,the increase is so great that the      
earliest  astronomers1 even with their  
imperfect modes of observation1 detected
  it4 ,hipparchus1 #abh years before    
,christ1 compared his own observations  
with those of ,timocharis1 #aec years   
before4 ,he found the solution of  the  
problem the same as ,diophantus found   
the solution of the squares  and cubes1 
by analysis4 ,in the time of            
,hipparchus1 the sun was at a  point #cj
 in advance of its present position1 for
 it then entered into  the constellation
 of ,aries near the vernal equinox4     
,at the present time the position of the
 equinoctial points shows a  recession  
of the whole1 #cj #a #dj4b4 ,at this    
rate of motion the  constellations      
called the ,signs of the ,zodiac are    
some distance from  the divisions of the
 ecliptic that bear their names4 ,at the
 rate  of #ej4a the whole revolution of 
the equinoctial points will be          

accomplished in #be1hfh years2 but this 
is again modified because the           
precession must vary in different       
centuries for the following reasons3    
the sun's motion is direct1 the         
precession retrograde2 therefore1 the   
sun arrives at the equator sooner than  
he does at the same star of             
observation4 ,now1 the tropical year is 
#cfe;d4 #e;h4 #dh #di4g2 and as the     
precession is exactly #ej4a1 we must    
suppose it takes some time for  the sun 
to move through that arc4 ,by direct    
observation it is found  that the time  
required for such translation is #bj    
#ai4f4 ,by adding  this amount to the   
tropical year we have the sidereal year 
of #cfe;d4  #f;h4 #i #i4f in mean solar 
days4 ,this amount of precession has    
been  on the increase since the days of 
its first recorder1 ,hipparchus1 as  the
 augmentation amounts to no less than   
#j4dee4 ,by adding that to the  known   
precession we find that the civil year  
is shorter now by #d4ba  than in his    

time2 but1 as a great division of time1 
the year can be  changed by this cause  
not more than #dc4    ,the action of the
 moon on the accumulation of matter at  
the earth's  equator is a source of     
disturbance that in very accurate       
observations  for time should be        
eliminated4 ,thus the moon1 with the    
conjoint action  of the sun1 depending  
on relative position1 causes the pole of
 the  equator to describe a small       
ellipse in the heavens with axes of     
#ah4e  for the major1 and #ac4fgd for   
the minor2 the longer axis being        
directed to the pole of the ecliptic4   
,this inequality has a period  of #ai   
years1--it being equal to the revolution
 of the nodes of the  lunar orbit4 ,the 
combination of these disturbances       
changes1 by a small  quantity1 the      
position of the polar axis of the earth 
in regard to the  stars1 but not in     
regard to its own surface4 ,with so many
 disturbing  causes1 we must add that of
 ,jupiter1 whose attraction is          

diminishing  the obliquity of the       
ecliptic by #j4deg according to ,m4     
,bessel4    ,the results of all these   
forces must affect the position of all  
the  stars and planets as seen from our 
earth4 ,their longitudes being  reckoned
 from the equinoxes1 the precession of  
these points would  increase the        
longitude2 but as it affects all the    
stars and planets  alike1 it would make 
no real or apparent change in their     
relative  positions4 ,nutation1 however1
 affects the celestial latitudes and    
longitudes1 as the real motion of the   
earth's polar axis changes the  relative
 positions4 ,so great is the change that
 our present pole star  has changed from
 #ab to #a #bd2 in regard to the        
celestial pole1 the  gradual            
approximation will continue until it is 
with #j #cj1 after  which it will leave 
the pole indefinitely until in #ab1icd  
years  ,lyr  will be the pole star4     
,so far we have given only the causes   
that affect the meridian1 and           

consequently our standard for time2 but 
that point being established  for the   
yearly and diurnal revolutions1 it      
becomes necessary to find  some means to
 divide the day into minute fractional  
parts1 such as  seconds and parts of    
seconds4 ,this1 it has been stated1 is  
effected  by means of an isochronous    
pendulum4 ,on this instrument no comment
 is  required but of the causes that    
disturb its accuracy much is needed4    
,in #afgb1 at ,cayenne1 the astronomer  
,richter1 while taking transits  of     
fixed stars1 found his clock lost #b #bh
 per day4 ,this was an  error that      
arrested his attention1 and he          
immediately attributed it  to some      
variation in the length of the          
pendulum--due to other causes  than     
atmospheric changes and expansion4 ,he  
determined the length of a  pendulum    
beating seconds in that latitude1 which 
was #e ,n4 in ,south  ,america4 ,he     
found that that pendulum was shorter    
than one beating  seconds in ,paris1 by 

#jhcc of an inch4 ,now1 if the earth was
 a sphere1  the attraction of           
gravitation at all places on its surface
 would be  equal1 and the oscillations  
of a pendulum would also be equal1  or  
- the disturbing effect of centrifugal  
force--an amount that can be  easily    
determined4 ,the real reason of the     
variation is found in the  configuration
 of the earth4    ,the amount of the    
attraction of gravitation at any point  
of the earth's  surface is found by the 
distance traversed by any body during   
the  first second of its fall4 ,the     
pendulum is a falling body1 and may be  
by  the same analysis reasoned on that  
pertains to the laws of gravitation2    
the centrifugal force is measured by any
 deflection from a tangent to  the      
earth's surface in a second4    ,it     
follows that the centrifugal force at   
the poles1 where there is  the least    
motion1 would not be equal to the force 
of gravitation1 and  at the equator must
 be exactly equal2 but the deflection of

 a circle  from a tangent measures the  
intensity of the earth's attraction1 and
  is equal to the versed sine of the arc
 described during that time1  the       
velocity of the earth's rotation being  
known1 the value of the  arc is         
deducible4 ,the centrifugal force at the
 equator is equal to  th part of the    
attraction of gravitation4 ,again1 the  
uniformity  of the earth's mass becomes 
an object of consideration4 ,assuming   
that  the figure of the earth is an     
ellipsoid of rotation1 we will show the 
relation that form bears to the equal   
oscillation of a pendulum4    ,taking   
the earth as a homogeneous mass1        
analysis gives us the certainty  that if
 the intensity of gravitation at the    
equator be taken as unity1  the increase
 of gravity to the poles eliminating the
 differences of  the centrifugal force  
must be  to #b4e1 the ratio of the      
centrifugal  force to that of           
gravitation at the equator4 ,now1 taking
 the #b4e of  4#cdf  #a_/aae4b1 this    

then must be the total increase of      
gravitation4  ,did we know the exact    
amount of increase at every point1 from 
the  equator to the poles1 a perfect map
 of the form of the earth could  be     
produced from calculation2 experiment   
being from physical causes  totally     
impracticable4 ,the following analysis1 
quoted from an eminent  physicist1 gives
 a very lucid idea of the reasoning3    
8,if the earth were a homogeneous sphere
 without rotation1 its  attraction on   
bodies on its surface would be          
everywhere equal4 ,if it  be elliptical 
and of variable density1 the force of   
gravity ought to  increase in intensity 
from the equator to the pole as unity   
plus  a constant quantity multiplied    
into the square of the sine of the      
latitude4 ,but for a spheroid in        
rotation the centrifugal varies by  the 
law of mechanics1 as the square of the  
sine of the latitude from  the equator1 
where it is greatest1 to the poles1     
where it is least4  ,and as it tends to 

make bodies fly off the surface1 it     
diminishes the  force of gravity by a   
small quantity4 ,hence1 by gravitation1 
which  is the difference of these two   
forces1 the fall of bodies ought to  be 
accelerated from the equator to the     
poles proportionably to the  square of  
the sine of the latitude1 and the weight
 of the body ought to  increase in that 
ratio40    ,assuming the above reasoning
 to be correct1 it follows1 that the    
rate  of descent of falling bodies will 
be accelerated in the transition  from  
the equator to the poles4 ,now1 it has  
been before stated that  the pendulum is
 a falling body2 therefore1 with the    
same length of  pendulum1 the           
oscillations at the pole should be      
faster than at the  equator4 ,theory1 in
 this case1 is verified2 for it has been
 proved by  experiments1 repeated again 
and again1 that a pendulum oscillating  
#hf1djj times in a mean day at the      
equator1 will give the same number of   
oscillations at any other point1        

provided its length is made longer in   
the exact ratio as the square of the    
sine of the latitude4    ,the sequence  
to be derived from all the foregoing    
considerations is1  that the whole      
decrease of gravitation from the equator
 to the poles  is #j4jje4addi1 which    
subtracted from the #a_/aee4b gives the 
amount  of compression of the earth to  
be nearly #a_/bhe4bf4 ,but this form  of
 the earth would give the excess of the 
equatorial axis over the  polar about   
#bf miles4 ,the measurement is confirmed
 by ,mr4 ,ivory  in his investigations  
on the five principal measurements of   
arcs of  the meridian in ,peru1 ,india1 
,france1 ,england1 and ,lapland4 ,he    
found  that the law required an         
ellipsoid of revolution whose equatorial
  radius should be #c1ifb4hbd miles1 and
 the polar #c1idi4ehe miles2 the        
difference is #ac4bci miles2 this       
quantity multiplied by two gives        
#bf4dgh as the excess of one diameter   
over the other4 ,thus1 by two  different

 processes the figure of the earth has  
been determined2 but  another remains   
that is the result of pure analysis1    
derived from the  nutation and          
precession of the equinoxes--for1 as    
explained before1  these effects are    
caused by the excess of matter at the   
earth's  equator4 ,the calculation does 
not lead us to certainty1 but it does   
show the compression to be comprised    
between the two fractions   and 4 ,there
 is this advantage in the lunar theory1 
that it takes  the earth as a whole1    
disregarding any irregularities of      
surface1 or  the local attractions that 
influence the pendulum--the difficulties
 of  measuring an arc of the meridian   
being an obstacle to perfect accuracy4  
,the form of the earth has1 however1 a  
value confined not alone to those       
interested in horology--it furnishes us 
with a standard of weights and          
measures4 ,in ,england and the ,united  
,states1 the pendulum is the unit of    
mensuration1 or at least the common     

standard from which measurement is      
derived4 ,it has been shown that1       
deducting the effects of nutation1 the  
axis of the earth's rotation is always  
in the same plane4 ,now1 the mass  being
 the same constant quantity1 a pendulum 
oscillating seconds at the  ,greenwich  
,observatory1 has been adopted by the   
,english ,government as  its standard of
 length4 ,oscillating in vacuo at the   
level of the sea1  at #fb ,fahr41       
,captain ,kater found its approximate   
length to be #ci4acic  inches2 as this  
must be invariable under the same       
circumstances1 it  becomes a standard   
for all time4 ,the ,french deduced their
 standard from  the measurement of the  
ten-millionth part of a quadrant of the 
meridian  passing through ,formentera   
and ,greenwich4 ,they have also adopted 
the  decimal system2 yet it seems to    
prove that nothing under the sun is     
new1 for over forty centuries ago the   
,chinese used the decimal system  in the
 division of degrees1 weights1 and      

measures4    ,the antiquity of the      
pendulum is also shown by the fact that 
the  ,arabs were in the habit of        
dividing the time in observations1 by   
its  oscillations1 when ,ibn ,junis1 in 
the year one thousand1 was making  his  
astronomical researches4 ,before we lose
 sight of the influence  of the form of 
the earth on the pendulum1 it may be    
well to state  another source of        
disturbance1 arising from the combined  
influence of  the earth's rotation and  
the fact that a body moving in its own  
plane  seeks to maintain that plane4 ,it
 will be seen from the very beautiful   
experiment showing the rotation of the  
earth1 that if a body like a  pendulum  
be suspended so as to be free in every  
direction1 and not be  influenced by the
 motion of the earth when set in        
oscillation in any  plane1 that that    
plane will preserve its line of motion1 
while the  earth in its motion beneath  
the body can be seen to slowly move1 as 
though the minute hand of a watch were  

made stationary while the dial          
revolved4 ,the same principle is the one
 that maintains the spinning-top  in a  
parallel position to the horizon1 or the
 gyrascope in its  apparently anomalous 
defiance of all the laws of gravitation4
 ,in the  pendulum this tendency to     
preserve the same plane of motion       
becomes a  cause of error--slight1 it is
 true1 but can be very easily remedied  
by  so placing it that the plane of     
oscillation shall be parallel to the    
equator4 ,it will be readily seen that  
this precaution will become more        
important as we recede from the equator2
 for if we were to suspend a  pendulum  
at the pole in a true line with the axis
 of rotation1 and if  the plane of      
vibration remained constant1 the earth  
would turn once  around that plane in   
the diurnal period4 ,during this time   
there would  be a continuous torsion on 
the point of suspension1 that would in  
time  materially affect the accuracy of 
the instrument4 ,the reasoning holds    

good for every latitude--degree of      
influence being the only difference4    
,having given the action of the earth's 
form1 mass1 and rotation on  the        
pendulum1 there remain the disturbances 
due to expansion and  contraction1 owing
 to changes of temperature and those of 
atmospheric  causes4 ,the astronomical  
points to be observed are somewhat too  
fully  laid down1 but it must be        
remembered that an exact science        
requires the  premises to be fully      
established before a sequence can be    
drawn4    ,as the standard of time      
depends on the passage of a star or the 
sun1 or  any known celestial object1 at 
a certain time across the meridian of   
the place where the observation is      
taken1 it was absolutely necessary  to  
give the modes of calculation1 together 
with the disturbing causes4  ,moreover1 
a full appreciation of the indebtedness 
of horology to  astronomy could not be  
obtained without a general knowledge of 
the  change of the position of the major

 axis of the orbit described by the     
earth around the sun4 ,also1 the        
difference between mean and apparent    
solar time was required to illustrate   
the use of the tables of equated  time1 
the necessity of which will become      
patent when the use of the  transit     
instrument for the establishment of     
time1 or a fixed standard1  is          
introduced4 ,also1 the disturbing       
effects of the sun and moon             
collectively and relatively as to       
position1 could not be passed1 as  they 
produce the precession of the equinoxes 
and the nutation of the  pole--essential
 elements in the computation of time4   
,watch and ,chronometer ,jewelling4     
,,number ,,one4      ,this whole subject
 is well worthy an article both in a    
scientific and  mechanical sense1       
whether we consider the delicacy of the 
operations  or the intractable character
 of the material operated on--for there 
has been no improvement in the          
horological trade of more importance to 

accuracy and durability of time-keepers4
    ,the substitution of stone for      
common brass or gold bearings1 was      
prompted by the inevitable wear of the  
holes from frequent cleaning1  and the  
abrasion of the pivots1 produced by the 
accumulation of  dust with viscid oil2  
the pivot being cut away1 or the hole   
opened  too large4 ,so long as the verge
 and cylinder were the prevailing       
escapements1 the necessity for jewelling
 was not so strongly felt1  except in   
the balance holes4 ,the introduction of 
the lever escapement  brought with it a 
better watch1--capable of more accurate 
time1 but  demanding an improved        
construction4    ,an ,italian1 in #agbc1
 first introduced the practice of using 
stone for  bearings4 ,he not only       
conceived the idea1 but was successful  
as an  artisan in making his own jewels2
 ingenious and skilful as he was1       
however1 he encountered obstacles almost
 insurmountable4    ,the art of cutting 
gems1 it is true1 was at that time well 

understood1  but no one had attempted to
 drill a hole in a hard stone fine      
enough  for a properly sized pivot4 ,the
 watches at that time that were jewelled
  could boast of nothing more than the  
balance holes1 and they were not        
pierced to let the pivot through4    ,it
 is a very difficult matter to polish a 
taper indentation in a stone1  even with
 modern appliances1 in consequence of   
the tendency to create  a tit at the    
bottom1--thus throwing the balance staff
 out of upright4  ,the difficulties in  
the then state of knowledge retarded the
 general  introduction of stone-work for
 many years4 ,the ,swiss1 however1      
seeing  the advantages derived1 finally 
struck out the various manipulations    
with success4 ,time and experience gave 
more skill1 and at the present  time it 
is impossible to find a ,swiss watch1   
even of the cheapest  class1 that is not
 jewelled in at least four holes4 ,the  
,english trade  adopted the art later2  
but even then it did not become general 

for many  years4 ,within a generation1  
only fine ,english levers were jewelled4
    ,the mere substitution of a harder  
substance was not the only  improvement2
 other conditions necessary to accuracy 
were insured4 ,the  hole could be made  
round--the material of such a character 
that no  chemical action could be       
effected on the oil used for            
lubrication1  and the vertical section  
of the hole could be made so as to      
present  the least amount of frictional 
surface1 yet still giving a perfectly   
polished bearing1 thus avoiding the     
cutting of the pivot4    ,the whole     
8modus operandi0 from the stone in the  
rough to the last  setting up is well   
worth the attention of the watch        
repairer1 and  certainly that of the    
manufacturer4    ,of the materials used 
in the trade1 the first and most        
important is  the diamond1 used only in 
the time-piece as an end-stone--but at  
the bench all-important1 as a means of  
making the other jewels4 ,the  diamond  

possesses the requisite susceptibility  
of polish1 combined with  greatest      
hardness of any substance known2 but    
this adamantine quality  precludes its  
being pierced with a through hole4      
,considered chemically1  the diamond is 
pure carbon1--its different varieties   
differing only  in structure--common    
charcoal1 its lowest--plumbago1 its     
intermediate  grade4 ,another variety1  
called the 8black diamond10 or 8diamond 
carbon10 occurs1 which is interesting as
 being a parallel with emery1  compared 
with crystallic sapphire4 ,the form of  
diamond most in use for  mechanical     
manipulations1 is almost always         
crystallized2 yet it will be  seen that 
the agglomerated form of diamond carbon 
plays no unimportant  part in jewelling4
 ,as a jewel1 no use is made of the     
diamond1 other  than as an end-stone4   
,marine chronometers1 in which the      
balance will  weigh from five to nine   
pennyweights1 are almost invariably     
furnished  with a diamond end-stone1 set

 in steel4 ,yet1 hard as the substance  
is1  it is often that a pivot will cut  
an indentation in its face4 ,the cause  
of this apparent anomaly is to be found 
in the structural character of  the gem1
 and its value4 ,the lapidary1 saving in
 weight as possible1  does not care1 in 
8,rose ,diamonds10 to pay attention to  
the lines of  cleavage4 ,if the face of 
the stone makes a slight angle with the 
strata of the jewel1 there occur        
innumerable small angles of extreme     
thinness--the pivot1 coming in contact  
with any of these thin portions1  may   
fracture it1 and the fragment1 becoming 
imbedded in the tempered  steel pivot1  
becomes a drilling tool4 ,in our        
experience we have had  marine          
chronometers sent for repair1 that have 
lost their rate so much  as to become   
utterly unreliable from this cause      
alone--the pivot having  produced an    
indentation of the stone1 creating more 
friction1 and thus  destroying the      
accuracy of the instrument4    ,as a    

general rule1 the rose diamonds sold for
 this purpose are  sufficiently good for
 general work4 ,in a very fine watch or 
chronometer  the stone should be        
selected with reference to its polish on
 the face1  and its parallelism in the  
lines of cleavage4 ,the diamond1        
however1  gets its great importance from
 being the only agent we can use in     
working other stones4 ,without it the   
whole art of jewelling would not  be    
practicable4 ,the various steps are all 
connected some way with  diamond in its 
different shapes4 8,bort10 the technical
 name for another  variety1 is merely   
fragments of the stone that have been   
cleaved off  from a gem in process of   
cutting1 or gems that have been cut1 but
 found  too full of flaws to become of  
use for ornamental jewelry purposes1    
the cost depending on the size1 varying 
from #e4ej to #ah per carat4  ,this     
8,bort0 is used as turning tools--the   
larger pieces being selected  and 8set0 
in a brass wire and used on the lathe1  

in the same manner1  and with the same  
facility1 as the common graver4 ,for    
tools1 even  the diamond is not of equal
 value--a pure white and crystalline in 
structure generally being too brittle   
7though hard7 to endure the  work4      
,among the workmen the 8,london smoke10 
a clouded1 brownish stone1  is most     
prized--it possessing the twofold       
qualities of toughness and  hardness4   
,another form of 8,bort0 comes in the   
shape of a small globule1 sometimes  the
 size of a pea2 it is crystallic1 and   
when fractured generally gives  very    
small1 indeed minute pieces of a needle 
shape4 ,these are carefully  selected1  
and form the drills with which the      
,english hole-maker  perforates the     
jewel4 ,these drills1 when found        
perfect1 for soundness1  form1 and size1
 are very highly prized by the workman1 
as the choice of  another1 together with
 the setting1 will often take a vast    
deal of time  and labor4    8,bort0 is  
also used in the making of the laps or  

mills with which  the jeweller reduces  
the stones to a condition for the lathe 
and  subsequent processes4 ,for this    
purpose such pieces as are not fit for  
cutting-tools1 or drills1 are selected4 
,a copper disk1 having been  first      
surfaced and turned off in the lathe1 is
 placed on a block or  small anvil2 each
 piece of stone is then separately      
placed on the  copper1 and driven in    
with a smart blow--care being taken that
 no place  shall occur in the disk that 
does not present1 in revolution1 some   
cutting point4 ,it would seem impossible
 to retain the diamond fragment1  but it
 must be remembered that the copper1    
being a very ductile metal1  receives   
the piece2 the first rubbing of a hard  
stone then burnishes  the burred edges  
of the indentations over every irregular
 face of the  diamond1 leaving only a   
cutting edge to project4 ,the rapidity  
with  which such a lap1 well charged1   
will reduce the hardest stone1 is       
somewhat marvellous4 ,it is the first   

tool used in jewelling1 and so          
important that a more detailed and      
explicit description of its make  will  
be given when the process of manufacture
 is treated upon4    ,diamond powder is 
equally as important as 8bort10 being   
used in nearly  every stage of          
jewel-making4 ,the coarsest charges the 
8skives0 or  saws used for splitting up 
the stone4 ,these skives are made of    
soft  sheet-iron1 and act on the same   
principle as the laps4 ,the finer       
grades1 in bulk1 resemble very much     
ordinary slate-pencil dust2  indeed1 the
 latter is often used as an             
adulteration4 ,this powder is  not      
uniform in fineness1 and the jewel-maker
 is under the necessity of  separating  
the different grades4 ,this is effected 
by a simple process  called 8floating   
off10 and is conducted as follows3 ,a   
certain quantity  of powder1 say a      
carat1 is put into a pint of pure sweet 
oil1 contained  in some such shallow    
vessel as a saucer4 ,depending on the   

fluidity of  the oil1 the mixture1 after
 being thoroughly incorporated1 is      
allowed  to stand undisturbed for about 
an hour or an hour and a half4 ,during  
this time1 owing to their greater       
gravity1 the largest particles are      
precipitated1 leaving held in suspension
 a powder of nearly uniform  fineness4  
,the mixture is now carefully decanted  
into another similar  vessel1 leaving   
the coarse powder at the bottom of the  
first4 ,this  coarse deposit is         
denominated ,no4 #a1 and is used for    
skives1 laps1 and  other rough purposes4
 ,the decanted mixture in the second    
vessel is  allowed to remain quiescent  
for twelve hours1 when the same         
operation  is performed2 and the third  
vessel now contains most of the oil1    
together with the finest particles of   
powder4 ,the precipitate from the       
second decantation is the ordinary      
opening powder2 the finest being for    
polishing both the holes and outsides of
 jewels1 and giving the final  finish to

 the faces of pallets1 roller pins1     
locking spring jewels1 etc4    ,the good
 workman is careful to keep the powder  
in this condition as  free as possible  
from any extraneous dust1 and above all 
to preserve  the different grades from  
any intermixture1 as a small quantity of
 a  coarser grade would destroy a finer 
one for all its purposes1 and the       
process of 8floating off0 would have to 
be repeated4    ,the most important     
stone in jewelling1 the diamond1 becomes
 more of an  agent of the manufacture   
than an object4    ,properly1 for       
jewelling the ruby and sapphire are     
pre-eminent2  inferior only to diamond  
in hardness1 possessing a sufficient    
degree  of toughness1 susceptible of an 
exquisite polish1 this 7for they  are   
one and the same7 stone is the favorite 
of the ,swiss1 ,english1  and ,american1
 for all high class work--the ,swiss1   
however1 using it  indiscriminately in  
all watches4    ,the ruby proper is of  
one color1 but in its varieties of      

intensity  may change to a very light   
pink4 ,when still lighter it is ranked a
  sapphire1 which comes in almost every 
possible color and shade1 from  ruby to 
a perfect transparent colorless crystal4
 ,this stone differs  in degrees of     
hardness and capacity of working--the   
hardest being a  greenish yellow1 in the
 shape of pebbles1 with very slightly   
rounded  edges1 difficult to work1 but  
forming the strongest and most perfect  
jewel known4    ,it must be remembered  
that this description gives the value of
 the ruby  and sapphire as a material   
for jewelling only4 ,for ornamental     
jewelry1  the value depending on color1 
of the most intense ruby or blue for    
sapphire1 together with brilliancy and  
weight4 ,the ruby and sapphire  are     
formed on an aluminum base1 the common  
emery being another form of  structural 
arrangement1 but of the same chemical   
constitution4    ,these stones possess  
every quality to make them the base of  
perfect  jewelling2 and still the       

chrysolite is equally in favor with most
  jewellers4 ,it is not quite so hard1  
but it is more easily worked and        
cheaper in price1 and it would be       
difficult to tell wherein it is         
inferior to either the ruby or sapphire4
 ,it has a yellowish tinge1  verging to 
the color of the olive4 ,as a stone for 
jewelry it is not  fashionable1 and only
 in ,persia is it valued4 ,there are1   
however1 some  very strong objections to
 its use by the workman2 it is not      
uniform  in hardness2 in polishing it   
will drag1 that is1 the surface will    
tear up in the process4 ,unfortunately  
the eye is not able to detect  the fault
 before working1 and it is found only   
when much preliminary  time and trouble 
has been expended4 ,it is susceptible1  
when good1 of a  perfect polish1 and is 
much used in chronometer work1          
especially for  jewelling the #dth hole1
 as its non-liability to fracture       
renders it  valuable4    8,aqua ,marine0
 is a brother to the emerald1 differing 

from it only in  intensity of color1 and
 composed of the same constituents4     
,these two  gems are the only ones in   
which the rare metal1 glucinum1 has been
  detected4 ,it is extensively used in  
the ,american and ,english watches1  but
 never in the ,swiss4 ,it is soft1 not  
much harder than quartz1 but  comes in  
large pieces1 perfectly transparent1 and
 of a color which  is that pure green of
 sea-water1 from which it takes its     
name1 8,aqua  ,marine40    ,the garnet  
in ,english watches plays an important  
part for pallets1 also  for roller-pins2
 a very soft stone1 but very porous4    
,when set in the  pallet with a pointed 
toothed wheel1 it is apt to act as a    
file from  its porosity1 cutting the end
 of the tooth4 ,this may be detected in 
any  pointed tooth lever watch1 by      
observing the color of the back of the  
tooth4 8,black vomit0 it used to be     
called in the ,boston factory4 ,most  of
 the garnet used is an ,oriental stone1 
the best quality coming in  bead form1  

the holes having been pierced by the    
natives4 ,the cost of  piercing the     
stone in ,europe or ,america would be   
far above its value4  ,the ,oriental is 
the best for ,horological purposes1     
though ,hungary and  ,bohemia furnish   
the most highly prized stones used for  
ornamental  purposes2 indeed1 in some   
,german towns the cutting and setting of
 the  garnet is a specialty1 giving     
employment to a large number of people4 
,and1 strange to say1 the best market   
for their sale is the ,united  ,states4 
,this comprises about all the stones    
used in watch and chronometer           
jewelling4 ,still in clock work the     
pallets are generally jewelled in       
agate1 a stone not at all suited to the 
purpose1 it having1 even in  the best   
specimens1 a decided stratification that
 prevents an uniform  surface being     
formed by any process4 ,the cornelian   
form of the agate  is not open to this  
objection1 and makes capital bearings   
for knife  edges of fine balances1 and  

compass stones for centres of magnetic  
needles4 ,for watch or chronometer      
purposes the only really useful  stones 
are sapphire1 ruby1 chrysolite1 and aqua
 marine--all possessing  peculiarities  
that deserve some remarks1 as they are  
of the utmost  importance to the hole   
maker4 ,the sapphire is the hardest     
stone1 next  to the diamond1 and yet    
specimens can be1 and are found1 so soft
 as  to drag in polishing4 ,again1 if   
stratified very clearly1 will 8fire     
crack0 in opening the hole4 ,the ruby is
 more uniform in its structure1  and is 
more highly prized on that account2 its 
hardness being all that  is necessary1  
while its susceptibility of receiving a 
high polish  is equal to that of the    
sapphire or chrysolite4 ,the aqua marine
 is  always uniform and may be polished 
both externally and in the hole with    
8tripoli10 saving something in diamond  
powder in the process of making4  ,in   
our estimation1 however1 the chrysolite 
is the most valuable of all  the stones4

 ,true1 when purchased in the rough1    
many pieces will be  found unfit for the
 jeweller's purpose2 but when the right 
quality is  found1 nothing can be better
 adapted to jewelling4 ,hard1 it is     
easily  wrought1 taking a peculiar      
unctious polish1 retaining oil in its   
most  limpid condition for a long time4 
,these stones form the general stock by 
and from which jewels are made4  ,the   
details of the various manufacturing    
manipulations1 the tools  used1 also the
 setting in the work1 together with the 
important item  of the screws1 will form
 the subject of the next article on     
,watch and  ,chronometer ,jewelling4    
,not having been able to get our        
engraving done  in time for publication1
 we are compelled to reserve the        
remainder for  the next number4         
,hints on ,clocks and ,clock-,making4   
,,number ,,one4      ,twenty-five years 
of hard labor amidst the dust and din of
 machinery1  with hands cramped1 and    
fingers stiffened by the continual use  

of  tools1 and with a brain constantly  
occupied in ringing the changes upon    
wheels and levers in their almost       
infinite combinations1--it requires a   
degree of courage to undertake to write 
anything that can be dignified  with the
 name of an 8article10 although it does 
propose to treat upon  a subject with   
which we are fairly familiar2 but it is 
consoling to  think that one is not     
expected to write for the pages of this 
practical  journal with the same degree 
of elegance and polish that should grace
  the columns of a review or magazine2  
that we can appear here as plain1       
practical mechanics1 and use good hard1 
round words to express our  ideas1      
backed by an experience which should add
 some weight--and we  welcome the       
appearance of the 8,american            
,horological ,journal10 which  is to    
serve a good purpose by bringing out the
 actual experience of  men who have     
grown gray in the art and mystery of    
clock-making1 and  preserving1 by means 

of the 8art preservative of all arts10  
their  dearly bought knowledge and      
experience1 for the benefit of those who
 in  their turn shall follow them2 and  
it will also benefit the people in      
general by giving information that will 
lead to the purchase of good  and       
tasteful clocks for household use4      
,that such a journal is needed to       
enlighten us1 is made plain by the  fact
 that in almost every newspaper we have 
a vivid account of some  wonderful clock
 8recently invented10 which may possess 
some merit1 but  they are so grossly    
exaggerated by some ignorant            
8penny-a-liner10 that  we are almost led
 to believe in the ,irishman's          
marvellous 8eight-day  clock1 that      
actually ran three weeks40 ,even the    
proverbially correct  8,scientific      
,american10 of which ,i am a constant   
reader1 has in its  issue of ,june      
#aith1 an account in its 8editorial     
summary0 of a clock in  ,france         
containing 8#ij1jjj wheels10 and perhaps

 the most curious part  of the mechanism
 is that which gives 8the additional day
 in leap-year10  etc4 ,now1 it will     
require but little knowledge of clocks  
to tell us  that one with #ij1jjj wheels
 was never made and never will be1 but  
8the  additional day in leap-year0 has  
been given by calendar clocks in this   
country since the year #ahec4    ,it is 
not proposed in the series of articles  
to follow1 to discuss  the early history
 of clocks4 ,reid and ,dennison have    
written enough  to convince the most    
skeptical that the clock is an old      
invention4  ,it is not important to us  
who invented the pendulum1 or this or   
that  escapement1 but who makes the best
 pendulum1 the best escapement1 the     
most perfect train of wheels and        
pinions4 ,these are vital points1 and   
we shall endeavor to give them that     
attention that their importance         
demands4 ,it is proper to state here    
that any assertion made1 or rule  given1
 has been tested1 and is the result     

merely of our experience1  and we do not
 claim that it is all there is of the   
subject2 for we are  aware that the     
experience of others may have led to    
results entirely  different2 but if all 
clock-makers will avail themselves of   
the columns  of this journal1 we shall  
not only become better acquainted by an 
exchange of ideas1 but better           
clock-makers4    ,the subject of wheels 
and pinions is of the greatest          
importance in  clock-making1 and the    
utmost care and skill are required to   
execute a  train which shall not only   
run with as little friction as possible1
  but the friction must be equal2 for if
 there is no variation in the  train    
force1 the escapement and pendulum will 
always be actuated by the  same amount  
of power1 and the performance of the    
clock can be relied  upon4 ,clock       
text-books do not fully impress this    
subject4 ,we find a  great deal upon    
this or that escapement1 and the        
different pendulums4  ,dennison has a   

couple of pages full of abstruse        
calculations upon a  method of shifting 
an extra weight upon a rod1 so that the 
going of a  clock can be varied one     
second per day2 but if his wheels and   
pinions  are not perfect1 a large tooth 
here and there will vary the clock more 
than that4    ,reid overawes us with his
 knowledge of the proper curves of the  
teeth  of wheels2 but it must have been 
only theory1 for his practice was to    
saw his teeth1 and his cycloids1        
epicycloids1 and hypocycloids were  left
 to the mercy of the 8topping file0 in  
the hands of his 8wheel  teeth          
finishers10 instead of shaping up the   
teeth in the engine1 as is  done now4   
,we have generally cut the wheels of    
fine clocks over several  times with    
different cutters before taking them    
from the engine2 the  last cutter having
 but one tooth1 which can be made       
perfect as to cut  and shape1 and1      
running with great speed1 will leave the
 teeth the  proper shape1 very smooth1  

and as true as the dial of the engine4  
,escape wheels1 especially1 require     
great care in cutting1 as the  teeth for
 dead-beat escapements are somewhat long
 and thin2 the least  inaccuracy is     
certain to cause trouble4 ,it is        
absolutely necessary that  the dial     
plate of the cutting engine should be   
perfectly true1 with  clean1 round      
holes1 and a perfect fitting index      
point1 with a cutter  arbor without end 
play or lateral motion--these are the   
essentials of a  good cutting engine1   
without which a good clock cannot be    
made4    ,we have generally made a      
practice1 upon the completion of the    
train for  a fine clock1 to put in the  
place of the escape-wheel a very light1 
well-balanced fly1 to prevent           
8backlash10 and a very fine soft cord   
on the barrel2 then hang on a very light
 weight2 so slight that--all  of the    
wheels being balanced1 and no oil upon  
the pivots--the fly  will move so slowly
 that its revolutions may be counted4   

,by taking  care that the weight be not 
too much in excess of the resistance1   
the  least inaccuracy in the wheels and 
pinions may be discovered by the        
difference in the velocity of the fly1  
or by its suddenly stopping1  which will
 be occasioned by any inequality in the 
train teeth1 which  would not have been 
discovered by the closest scrutiny4 ,it 
was by means  of this test that we      
discovered an inaccuracy in a pinion1   
caused by  hardening1 which could not   
have been discovered by a less delicate 
test4    ,the wheels in the train should
 be as light as possible1 for as the    
whole train is stopped every time a     
tooth drops on the pallets1 it is  plain
 that the driving weight must overcome  
the inertia as well as the  friction of 
the train at every beat4 ,to this end it
 has been customary  to 8arm out0 the   
wheels1 leaving a very light rim        
supported by light  arms1 the wheels    
being generally of cast brass1 turned   
up1 and cut1  then lightened4 ,we       

followed this plan for some time1 but   
abandoned it1  as we found great        
difficulty in making a perfectly round  
wheel4 ,the  arms serve as posts to     
support the rim in cutting or turning1  
but the  space between is very apt to   
spring down4 ,we prefer making the      
wheels  of fine hard-rolled sheet brass2
 it is superior to cast brass1 much     
finer1 harder1 and more durable1 and is 
freer from flaws4 ,after the  wheels are
 cut1 they are turned out on each side1 
leaving a thin web in  the centre2 they 
can be made lighter1 finished easier1   
and are round4    ,as to the shape of   
the teeth in clock-wheels1 the subject  
has been so  ably treated by ,reid1     
,dennison1 and ,prof4 ,willis 7who has  
invented an  instrument to assist in    
laying out the curves for the teeth of  
wheels71  that we shall not attempt it  
in this paper2 besides1 there is so     
little  of the entire theory that can be
 applied to a clock-wheel of two and  a 
half inches in diameter1 with #abj to   

#adj teeth1 farther than to  leave the  
wheel and pinion of the proper diameter1
 that we consider it  unnecessary2 for  
if makers of regulators and other fine  
clocks will  use pinions of #af or #bj  
teeth1 the friction or driving is all   
after the  line of centres1 and the     
whole subject of cycloids1 epicycloids1 
and  hypocycloids is reduced to a very  
small point1 and might be said to       
8vanish into thin air40    ,having given
 only a few practical hints1 and not yet
 crossed the  threshold of the subject1 
we propose to continue from month to    
month--if the readers of the ,,journal  
do not weary--the discussion of  the    
various parts that go to make the sum   
total of a fine clock1 with  notices of 
the various clocks made in this country4
           99       99       99       99
       99    ,it certainly comes within 
the province1 and is the duty1 of a     
journal  devoted to ,horology1 to make a
 note of any and all the new            
improvements  that pertain to the       

science4 ,we give1 then1 some few1 the  
merits of  which have struck us as being
 a very important matter of             
consideration4    ,the best clock       
time-keeper is not absolutely perfect1  
so its rate must  be kept2 but the      
watchmaker ordinarily has no means of   
correcting the  error of his regulator1 
until the accumulation renders it a     
serious  inconvenience4 ,did he possess 
a ,transit instrument1 properly set and 
adjusted for meridian1 together with the
 required books and knowledge  of       
observing1 he could from day to day     
correct his clock and keep  accurate    
time2 but these are all expensive1 as   
well as involving time  and labor4      
,suited to the wants of the artisan is a
 little instrument  called the          
,dipleidescope2 simple in its           
construction1 and not liable  to get out
 of position or order1 it forms the best
 substitute for the  transit we have    
seen4 ,it is founded on the theory that 
the double  reflection from the two     

surfaces of planes at an angle of #fj   
will  coincide when the object reflected
 is in a true line with half the base   
of the whole triangle4 ,having a prism  
cut in an equilateral triangle1  one    
angle is set directly down toward the   
centre of the earth1 the base  being    
brought parallel with the line of the   
horizon4 ,now1 if the axis  of the prism
 is in a line with the meridian1 a      
reflection of the sun  will appear1 at  
the instant of crossing the meridian1 on
 itself--that  is1 there would be but   
one image4 ,if the instrument is well   
made1  there can be no doubt of its     
accuracy and value to those who1 wishing
  to verify their time1 are not situated
 so as to use a transit4    ,another    
improvement is a ,bench-,key for        
watchmaker's use4 ,no one who has  had  
any experience at the bench but will    
appreciate an article that  facilitates 
the setting of time-pieces for his      
customers4 ,in winding1  it is equally  
valuable4 ,it is not dependent for its  

strength of torsion  on the spring-chuck
 principle1 the power being applied     
close to the  square by means of a pin  
that passes through the key4    ,hall's 
,patent ,cutting ,nippers are a positive
 desideratum2 a large  wire can be cut  
off without the least jar to the hand1  
the leverage  is so great4 ,the smallest
 sizes are suitable to the ordinary run 
of watch-work1 and can be used in       
clock-work better than any              
cutting-plyers extant4 ,strong and      
durable1 they possess one quality  that 
all watchmakers will appreciate--if a   
cutting-jaw is broken it can  be        
replaced by another4          ,greenwich
 ,observatory4      ,about two hundred  
years ago1 ,england began to take a lead
 in the  mercantile commerce of the     
world2 her ships were daily passing     
across  the ,atlantic1 and ,india also  
was beginning to attract her attention4 
,it was therefore of the utmost         
importance that navigators should be    
enabled to find their longitude when at 

sea1 independently of watches  or       
clocks2 and a reward was offered to any 
one who should discover a  method by    
which this result might be obtained4    
,the plan proposed was1 that the angular
 distance of the moon from  certain     
stars should be calculated beforehand1  
and published1 so that1  for example1 it
 might be stated that at ten minutes and
 five seconds  past nine on such a day1 
the moon should be distant from ,mars   
#dj  degrees4 ,if from a ship in the    
middle of the ,atlantic1 ,mars and the  
moon were found to be #dj degrees apart1
 then it would be known that the  time  
in ,england was ten minutes and five    
seconds past nine4    ,here1 then1 was  
one item ascertained1 and the method was
 a good one2  but in consequence of the 
want of accuracy as regarded the moon's 
motions1 and the exact positions of the 
stars1 it could not be  practically     
carried out4    ,under these            
circumstances1 ,charles ,,ii4 decided   
that a national  observatory should be  

built1 and an astronomer appointed2 and 
a site  was at once selected for the    
building4 ,wren1 the architect1 selected
  ,greenwich ,park as the most suitable 
locality1 because from thence  vessels  
passing up and down the ,thames might   
see the time-signals1  and also because 
there was a commanding view north and   
south from  the hill selected for the   
site4 ,the observatory was completed in 
#afgf1 and ,flamsteed1 the chief        
astronomer1 immediately commenced his   
observations1 but with very imperfect   
instruments of his own4 ,during  thirty 
years1 ,flamsteed labored indefatigably1
 and formed a valuable  catalogue of    
stars1 and made a vast collection of    
lunar observations4  ,he was succeeded  
by ,halley1 who carried on similar      
observations2 and  from that time to the
 present1 ,greenwich ,observatory has   
been our  head-quarters for astronomical
 observations4    ,the work carried on  
at ,greenwich is entirely practical1 and
 consists  in forming a catalogue of    

stars and planets1 and so watching them 
that every change in their movements is 
at once discovered4 ,now that  this work
 has been performed for several years1  
the movements of the  principal         
celestial bodies have been so accurately
 determined1 that the  ,nautical        
,almanac--the official guide on these   
subjects--is published  four years in   
advance1 and thus we find that on a     
particular night in  #ahfh1 the moon    
will be at a certain angular distance   
from a star1 and  the second satellite  
of ,jupiter will disappear at a         
particular instant4  ,on the exterior   
wall of the observatory there is a large
 electric  clock1 which1 being placed in
 8contact0 with the various other clocks
  in the observatory1 indicates exact   
,greenwich time4 ,the face of this      
clock shows twenty-four hours1 so that  
it requires that a novice should  look  
at it twice before comparing his watch4 
,on the left of this clock  are metal   
bars let into the wall1 each of which   

represents the length  of a standard    
measure1 such as a yard1 foot1 etc4 ,and
 let us here say  a few words about     
these standards4 ,to the uninitiated a  
yard is simply  three feet1 and a foot  
is twelve inches--an inch being1 we are 
told in  our 8,tables10 the length of   
three barleycorns4 ,now1 as the length  
of  a barleycorn varies considerably1 it
 requires something more definite  than 
this to determine our national measures4
 ,thus1 the question1 what  is a foot8  
is more difficult to answer than at     
first sight appears4  ,many years ago   
the ,french perceived the difficulty    
appertaining to the  national standard1 
and they1 therefore1 decided that a     
metre should be  the ten-millionth part 
of one-fourth of the earth's            
circumference--that  is1 ten-millionth  
of the distance from the ,equator to the
 ,pole4 ,but  here another difficulty   
was encountered1 because different      
calculators  found this arc of different
 lengths4 ,by law1 however1 it was      

decided  that one measurement only was  
correct1 and so the metre was fixed at  
#c4jgid ,paris feet2 though since then1 
more accurate observations and  improved
 instruments have shown these measured  
acres to have been  very incorrectly    
ascertained1 and thus the ,french method
 failed when  practically tried4    ,the
 length of a seconds pendulum           
oscillating in a certain latitude has   
been our method of obtaining a standard2
 but this also has its weak  points1 so 
that to obtain a constant standard it is
 necessary to have  some pattern which  
is unchangeable1 and thus a metal has   
been chosen  that expands or contracts  
but little either with heat or cold2 and
  this1 at a certain temperature1 is the
 standard measure1 and such a  standard 
may be seen on the exterior wall of     
,greenwich ,observatory4    ,on entering
 the doorway--which is guarded by a     
,greenwich pensioner1  who will possibly
 first peep at the visitor1 in order to 
see who  the individual may be who is   

desirous to tread within the sacred     
precincts--one finds a court-yard1 on   
the left of which are the  transit-room1
 the computing-room1 and the            
chronometer-room4 ,the  transit room    
takes its name from the instrument      
therein1 which is  a large 8transit40   
,this consists of a large telescope1 the
 outside  of which is not unlike a heavy
 cannon1 as it is of solid iron4 ,the   
instrument is supported by trunnions1   
which allow the telescope to be         
elevated or depressed to point south or 
north1 and1 in fact1 to make  a complete
 revolution1 but never to diverge from  
the north or south  line4 ,the          
magnifying power of this instrument is  
not very great1 so  that it admits      
plenty of light1 for it is intended1 not
 as a searcher  for or for gazing at    
celestial objects1 but for the purpose  
of noting  the exact time at which stars
 and planets pass south or north of     
,greenwich4 ,upon looking through this  
telescope1 the observer's eye  is first 

attracted by a vertical row of what seem
 to be iron bars1  placed at equal      
distances from each other4 ,these1      
however1 prove to be  only spiders'     
webs1 and are used for the purpose of   
taking the time  of passage of a star   
over each wire1 and thus to ascertain   
the exact  instant of its being in the  
centre of the telescope4 ,during even   
the  finest and calmest nights1 there is
 occasionally found a tremulousness  in 
the instrument1 which1 as it is rigidly 
fixed to the walls of the  building1    
must be due to a slight vibration in the
 ground itself4 ,thus1  many a feeble   
earthquake unfelt by the outsider may be
 perceived by the  astronomer by the aid
 of his delicate instruments4    ,the   
various stars seem to be travelling at  
an immense rate when  seen in the field 
of the transit telescope1 and it is     
really nervous  work noting the exact   
time when each wire is passed4 ,the     
experienced  observer1 however1 not only
 will give the minute and second1 but   

also  the decimal of a second when the  
star was on the wire4 ,the result is    
obtained by counting the beats of a     
clock the face of which is opposite  the
 observer4 ,thus1 if at three the star  
seems as much short of the  wire as at  
four it had passed it1 then #c4e might  
be the instant of  8transit40    ,at    
noon each day the sun's passage is      
observed by nearly the whole  staff of  
observers4 ,one individual looks through
 the telescope1 and  gives the time for 
each wire1 while others examine a       
variety of  micrometers in order to     
ascertain the fractional parts of       
seconds1  etc41--these micrometers being
 placed at the side of the instrument4  
,in the morning1 the principal work     
consists in making what are termed  the 
8reductions0 to the observations of the 
previous night4 ,these  reductions are  
the corrections requisite for the slight
 instrumental  inaccuracy1 for the      
refraction of the atmosphere1 and for   
the known  constant error of the        

observer4 ,when1 therefore1 a bright    
winter's  night has occurred1 the work  
on the following morning is usually very
  heavy4 ,at noon the sun's time of     
transit is taken1 and at one o'clock    
the 8ball0 is dropped1 by means of which
 the various vessels in the  ,docks and 
in the ,thames set their chronometers1  
or ascertain their  rate4 ,in addition  
to this1 the time is sent by electricity
 to ,deal and  one or two other         
seaports1 in order that every vessel may
 be able to  know the accurate time1 if 
within sight of those places4    ,not   
the least interesting portion of the    
observatory is the chronometer  room4   
,for a very small charge1 manufacturers 
or owners may have their  chronometers  
rated at ,greenwich1 which is           
accomplished in the following  manner3  
,the chronometer is placed in the       
chronometer room1 and compared with  the
 large electric clock in the room1 this 
clock being kept in order  by the stars4
 ,each day the chronometer is examined1 

and thus its rate  is ascertained in its
 then temperature4 ,it is afterwards    
placed in a  sort of closet warmed by   
gas1 a condition supposed to represent  
the  tropics1 and it is there kept for a
 certain period1 being tested each  day 
as before4 ,this change of temperature  
is found to produce very  little effect 
on the best instruments1 which1 when    
they have passed  the ordeal1 are       
returned to the owners with their       
character ticketed  to them4 ,some      
hundred chronometers are often placed in
 this room2 and  to compare them is a   
science1 the 8expert0 by a glance       
discovering the  difference between the 
two instruments1 whilst a novice would  
require  to mentally add or subtract1   
and thus slowly to arrive at the same   
results4    ,as soon as it becomes dark 
enough to see stars by the aid of a     
telescope1 one of the staff commences   
his observations4 ,these are  continued 
during the night2 and a register is kept
 of each star1  planet1 comet or moon1  

which is 8doctored0 in the morning by   
the  computers4    ,as all mortals are  
fallible1 it is desirable to bring      
machinery into  use where possible1 and 
this has been managed in connection with
  astronomical observations4 ,instead of
 the computer registering by  judgment  
the time of a star's transit over the   
various wires1 he  strikes a small      
indicator1 which1 completing the        
electric circuit1  causes a pricker to  
fall and make a hole in a piece of paper
 that  is attached to a slowly revolving
 barrel4 ,each time the star passes  a  
wire1 the pricker descends and leaves   
its mark2 and the interval  between     
these marks being measured by scale1 the
 mean time of transit  may be obtained4 
,there is usually a feeling of the      
sublime that comes over us when we      
reflect upon the vast unexplored regions
 of space1 or contemplate the  stellar  
world that shines upon us4 ,the         
magnitude and grandeur of some  of the  
planets in the solar system strike us   

with a feeling of awe  and wonder1 while
 we are puzzled at the mysteries        
attending comets1  double stars1 nebul1 
etc4 ,no such feelings or sentiments1   
however1  are allowed to enter into the 
constitution or mind of an observer at  
,greenwich4 ,saturn1 the glorious ringed
 planet1 with its galaxy of  moons1 is  
simply 8,saturn1 ,right ,ascension #aj  
hours #h min4 #ab sec41  ,north         
declination #af #ab #b40 ,anything      
appertaining to the physical            
constitution1 the probable cause of the 
ring1 or the object of so  grand an orb1
 does not come within the range of the  
observations at  ,greenwich1 which are  
limited to bare matter-of-fact business 
work4    ,the southern portion of the   
observatory ground is devoted to  the   
investigation of meteorological         
subjects1 and is under the              
superintendence of ,mr4 ,glaisher1 who  
is now well known as an aerial  voyager4
 ,it is here that an exact record is    
kept of the amount of  rain that daily  

falls1 of the direction and force of the
 wind1 of  the magnetic changes1 of the 
temperature1 amount of ozone1 etc4--all 
matters which may1 and probably will1   
lead us eventually to the  discovery of 
some laws connected with the states of  
weather1 and enable  us to predict what 
may be expected from day to day4 ,whilst
 we are now  able to calculate to a few 
seconds1 and for years in advance1 the  
instant when an eclipse may occur1 and  
to explain the causes of the  various   
planetary movements1 yet we are in a sad
 state of ignorance  as regards the     
causes of hurricanes1 thunder-storms1   
continued rains  and droughts2 and thus 
we find that all the would-be prophets  
who  from time to time spring up and    
oracularly announce a coming frost  or  
fine weather1 or the reverse1 are       
perpetually meeting with most  signal   
failures1 which1 however1 does not deter
 future adventurers from  attempting to 
gain a cheap temporary renown by trying 
their luck at a  prophecy4    ,the      

perpetual accumulation of facts at      
,greenwich1 whether these be of  an     
astronomical nature1 or appertaining to 
the air we breathe and its  subtle      
changes1 is a proceeding that must      
eventually lead us on to a  correct     
knowledge of the laws which govern these
 matters1 and also keep  us acquainted  
with any variations that may be         
occurring in the elements  that surround
 us4    ,the order and quietness        
necessary in such calculations as those 
carried  on at ,greenwich prevent it    
from being a 8show0 establishment1 and  
hence visitors are not admitted except  
on special business4 ,then1  however1   
every aid and assistance are offered to 
the student and  inquirer2 the use of   
books and instruments is freely given1  
and such  information supplied as the   
little spare time of those belonging to 
the  establishment enables them to      
afford4 ,thus a visit to or a period of 
study at ,greenwich ,observatory will   
amply repay those who wish to gain  the 

latest and most accurate information on 
astronomical subjects1 or  to practise  
themselves at the adjustments and use of
 the instruments2  and to those who have
 not such opportunity1 we offer this    
slight sketch4      ,chambers' ,journal4
          ,pinions4      ,well made as  
to truth of centring1 of division1 of   
form of leaves1 and  polish1 are1 as the
 trade well knows1 of vital importance  
to the value  of the time-piece4    ,the
 making and finishing is one of the most
 troublesome1 as well  as most expensive
 of all the processes in watch work4    
,the nature  of the material renders it 
difficult as it approaches so nearly in 
hardness to the tools used in cutting4  
,in the ordinary ,yankee clock1  the    
lantern pinion has entirely superseded  
the solid leaf1 which  substitution was 
the greatest element of success in their
 cheap  construction4 ,the lantern      
pinion is really a nearer approximation 
to  the required anti-frictional form   
than a majority of cut pinions in       

ordinary clocks4 ,in the process of     
manufacture of the cut variety1 the     
first consideration is the quality of   
the steel to be used4 ,for this  purpose
 it should be carefully selected by     
trial1 thus ascertaining  its fineness1 
uniformity1 softness when annealed1     
together with its  capacity for taking a
 good temper1 with the least amount of  
springing  during the hardening process4
 ,very few pinions are cut from the     
solid  piece--the drawn pinion wire     
being quite good enough1 when milled and
  finished1 for the ordinary run of     
watch work4    ,the steel wire having   
been selected1 the first process is to  
cut it  up in lengths a trifle larger   
than the required pinion4 ,the separated
  pieces are then centred with care1 and
 having been placed in a lathe1  the    
staff and pivot are turned up to nearly 
the required gauge1 leaving  a portion  
of the whole piece the full size for the
 leaves4 ,they are  now taken to the    
milling tool to have the proper form    

given to the  leaves4 ,as this form is  
of the highest importance1 it may be as 
well to  give here the reasons4         
,supposing a wheel of #fj teeth1        
depthing into a  pinion of #h leaves1 it
 can readily be seen that the arc of the
 motion  of the wheel tooth is of       
greater radius than that of the leaf of 
the  pinion1 and it follows that if the 
teeth and the leaves are made in  taper 
form with straight sections1 there must 
occur a sliding motion  on the surfaces 
of both--the power thus absorbed being  
totally wasted2  but if we curve the    
surfaces we may approach a form so      
nearly perfect  that the wheel teeth1   
being motors1 really roll on the leaves1
 avoiding  almost entirely the friction 
caused by sliding2 the necessity for    
this  curvature becoming greater the    
more the wheel exceeds the pinion in    
diameter4 ,this curve1 which has been   
demonstrated by very profound           
mathematical researches1 is the         
8epicycloidal20 theoretically it should 

give no more sliding motion than the    
surfaces of two plain wheels  revolving 
on each other4 ,to obtain this perfect  
form1 very great pains  have been taken 
and expenses incurred1 especially by the
 makers of the  best time-keepers4      
,in the ,american factories the cutters 
are very elaborately made1  the section 
being an object of great solicitude--it 
being an exact  counterpart of the space
 between any two leaves1 and also of    
one-half  the top of the leaf from the  
curvature to the point1 so that in      
milling1 the space made by the cutter is
 its shape1 leaving the leaf  of the    
proper form4 ,generally the pinion      
passes under two cutters2 the  first to 
strike down the rough stock1 the other  
to dress it to size and  shape1 with a  
light cut4 ,the care and skill required 
to make these is  certainly very great1 
and it is a proof of the wonderful      
ingenuity of  man that they are made so 
perfect as to shape and cutting power4  
,a very ingenious device is used for    

dividing the leaves under the  cutter1  
which revolves at a moderate speed over 
a slide1 carrying a  pair of centres1   
between which the turned up piece of    
pinion wire is  placed4 ,the slide is   
now pushed up to and under the cutter1  
and in  its passage as much of a cut is 
taken as is desirable2 in drawing  back 
the slide the fresh cut space passes    
under a flat piece of thin  steel1      
screwed on the frame1 and set at a      
slight angle to the axis of  the        
centres4 ,on moving the slide towards   
the cutter for a fresh cut1  the steel  
plate takes the last cut1 and in passing
 by it the pinion  is turned just as    
much as the angularity of the plate1    
which must be  just one leaf4 ,by this  
very clever device the division is      
effected  without an index plate4 ,this 
process1 however1 is not good enough for
  work intended to be very accurate--the
 pinion wire not being always1 or       
indeed rarely correctly divided1 the    
original error will be perpetuated  in  

all the subsequent processes4 ,these are
 all milled1 with oil or soda  water for
 a lubricator1 and it follows that the  
speed of the cutter is  regulated to get
 the greatest cut without dulling the   
tool4 ,when dull1  however1 the mill is 
sharpened on the face of the cutting    
tooth by  means of small grinders of    
iron1 using ,arkansas oil-stone dust for
 the  first grinding1 and giving the    
necessary delicacy of the edge by means 
of crocus1 or sharp1 followed1 when fine
 work is needed1 by rouge4    ,it is    
necessary that this care should be      
taken1 for if the edge is  left coarse  
it will become speedily dulled1 and     
leave a very unequal  and rough surface 
on the cut of the pinion1 which in the  
subsequent  grinding gives rise to error
 in shape and size4 ,the pinions1 thus  
cut  to gauge1 are dried in sawdust1    
hardened1 and tempered2 the staff and   
pivots are now turned up to size1 and   
then pass to the polishers4 ,in  the    
factory they are finished by means of   

what are called ,wig-,wags1  which it   
may be interesting to the reader to have
 a general description  of4    ,two ,vs 
are arranged as centres1 the pinion is  
placed between them1  the circular parts
 resting in each ,v1 but free to turn on
 its own  axis4 ,immediately above the  
,vs is a frame on which a slide1        
carrying  the polisher1 may             
traverse--generally about two inches4   
,this slide is  movable vertically so as
 to accommodate itself to the pinion2   
attached  to the slide is a connection  
which leads to a vertical lever1 which  
is put in motion from a crank on the    
counter shaft4 ,the grinding is         
effected by bringing the grinder1       
charged with oil-stone dust in oil1  in 
one of the spaces of the pinion1 which1 
of course1 is so arranged  as to bring  
it parallel and central with the        
grinder4 ,the power being  applied1 the 
slide takes a very rapid reciprocatory  
motion1 and the  face of the grinder1 so
 charged1 rapidly reduces the uneven    

surface  left by the cutter to what is  
called the gray4    ,the form of this   
grinder must be as perfect as the       
cutters1 and the  care taken to get the 
requisite parallelism is in equal       
proportion1  and in all the best        
polishers is planed up while in its     
position4 ,the  grinder is composed of  
tin and lead1 with sometimes a slight   
admixture  of antimony1 rolled to an    
even thickness1 cut off in suitable     
lengths1  and then mounted in the       
carrier of the ,wig-,wag to be planed up
 to  shape4 ,there are too many minute  
adjustments in the machine to render a  
full description in this article        
admissible4 ,it is large compared with  
the work it has to perform1 but it is   
very admirably made1 as indeed  all the 
tools are1 in the ,american factories4  
,the polishing of the leaves is the next
 step1 and this is effected by  means   
precisely the same as grinding4 ,in each
 stage the pinions are  thoroughly      
cleansed before entering on another4    

,the polisher is made  precisely like   
the grinder2 but instead of oil-stone   
dust1 crocus mixed  with oil is         
substituted4 ,owing to the less cutting 
quality of the  material used1 the      
polisher loses its form sooner than the 
grinder1  and has to be more frequently 
reshaped4 ,in very fine work the crocus 
is succeeded by fine well-levigated     
rouge to bring up that jet black        
polish1 which is considered a mark of   
quality by chronometer and watch        
makers4    ,with the exception of       
turning up the staff and pivots1 all the
 work  hitherto described has been      
expended on the leaves--a very tedious  
process1 yet done1 when the tools and   
materials are in proper order1  with    
marvellous rapidity2 but tedious as     
these have been1 there are two  others  
quite as much so before the leaves are  
finished4    ,the ends are to be        
faced--they must be flat 7that is a true
 plane7 and  receive the same finish    
that the leaves took1 and is effected by

 the  wig-wag2 only the pinion revolves 
between centres1 at a high speed1 the   
grinder being brought up to the turned  
face4 ,two motions operate--one         
rectilinear1 the other circular--the    
result being a compound motion  which   
prevents the grinder from touching the  
same spot twice in  succession4 ,to     
effect this more surely1 the operator   
gives the grinder  a slight vibratory   
vertical motion4 ,the polishing of the  
two faces is  effected in the same      
manner as the grinding2 in all cases the
 cutting  face of the grinders and      
polishers being kept in a plane         
perpendicular  to the axis of the       
pinion1 both vertical and horizontal4   
,the staff and pivots being in the same 
condition they came from the  lathe1 the
 next step is to grind and polish them4 
,before1 however1 we  treat on this     
process1 it may not be amiss to give the
 general watch  repairer a process by   
which the facing may be done on a small 
scale4    ,as a rule1 when the watch    

repairer has to replace a pinion he     
selects  one from the material dealer1  
finished in the leaves1 but not on the  
ends or faces4 ,the following operations
 are simple1 and any one may  finish    
these faces with little trouble4 ,having
 turned up your pivots  and squared down
 the face of the leaves with the turning
 tool1 grind  it in the lathe by means  
of a ring of metal1 the inside diameter 
being  somewhat larger than the diameter
 of the staff4 ,this ring is held       
between two centres1 thus allowing it a 
vibratory motion1 so that  when it comes
 up to the face it accommodates itself  
to its plane1 and  thus has no tendency 
to force it out of a true flat2 the     
ring1 being  larger than the staff or   
pivot1 admits a small lateral motion1   
enough  to effect a continuous change of
 surface4 ,the same little tool may be  
used for polishing by substituting      
another polisher and using crocus  and  
rouge4 ,for the repairer1 perhaps on    
general work the rouge would  be        

superfluous4 ,vienna lime1 used with a  
little slip of boxwood1  brings up a    
very fine and brilliant polish1 and in  
replacing new work  in an injured       
time-piece1 the steel may always be     
polished with great  rapidity by using  
the lime on the gray surface left from  
the oil-stone  dust2 being quickly done 
and affording a very handsome finish4   
,to resume the consideration of the     
pinion1 the last stage is the  polishing
 of the circular portions4 ,here again  
the wig-wag is the  most useful tool1   
but it operates somewhat differently1   
for the  grinder or polisher is pressed 
down by the finger of the operator1  the
 pinion being held between the centres  
of a small lathe attached  to the       
wig-wag2 the staff is first ground and  
polished as the leaves  have been       
before1 and this is the last operation  
performed with the  pinion between      
centres4 ,from this stage it is chucked 
in a lathe very  peculiarly fitted1 the 
mandrel being hollow2 and in it is      

fitted what  is called a pump-centre1   
which is movable in direction of the    
axis of  the mandrel1 and capable of    
being securely fastened at any desired  
point4 ,on the nose of the mandrel is   
secured a hollow steel chuck1  the two  
sides of which have been filed out1 thus
 leaving an open  space between the end 
of the pump-centre and the end of the   
chuck4 ,on  this end a small steel      
plate1 extremely thin1 is fastened by   
means  of shellac1 and a hole drilled in
 the plate capable of taking in the     
chamfer on the shoulder of the pivot4   
,the pump-centre being drawn  back1 the 
pinion is introduced into the chuck1 the
 pivot placed in the  hole in the steel 
plate1 and the pump centre is drawn     
forward until  it forces the chamfer to 
fill the hole2 the pivot projecting from
  the chuck is now ready for all the    
grinding and polishing processes4  ,here
 the wig-wag steps in again1 and from   
the delicacy of the pivots  is modified 
to suit the case2 this is done by having

 a polisher hung  in the wig-wag on     
centres1 so it may revolve2 when in     
operation one  side of the polisher     
rests on the pivot1 the other on a ruby 
placed  in a screw1 and which screw     
enables the operative to insure the     
parallelism of the pivot4 ,the ends of  
the pivots are next rounded off  and    
finished in another set of tools4 ,the  
pinion is now ready for use1  assuming  
it to be of the proper gauge4 ,in the   
,american watches the  scape and fourth 
wheels are generally staked on the staff
 pinch tight2  the third and centre are 
staked on the pinion leaves1 a rebate   
having  been turned down on the ends1   
the wheel set on the shoulder1 and the  
projecting ends of the leaves riveted   
down4 ,this has not been designed  as an
 exhaustive article on pinions2 it is   
merely intended to open the  subject as 
pursued in the factories4 ,there is much
 more to be said2 and  the various      
processes on the small scale1 as        
performed by the ,swiss  and ,english1  

together with their tools1 will bear    
more than a general  description1 as    
they are applicable at any watch bench4 
,the subject will be continued1 in the  
effort to give a full and useful        
article4          ,new ,three-,pin      
,escapement4      ,a contributor to the 
,london ,horological ,journal gives the 
following  description of his invention3
     8,the merit of this escapement is  
in a newly invented escape-wheel   which
 is self-locking and requires no banking
 pins2 the pallets are   curved inside  
the impulse and outside the locking1 to 
work with the   curved points of the    
teeth of the wheel2 being made of gold  
the wheel   will go without oil4 ,from  
its form it has the power of double     
impulse   and double locking with the   
lever4 ,the first takes place at the    
discharge of the escapement1 the second 
does not act unless the watch   receives
 a sudden motion1 and then the pin or   
pallet in the roller   strikes lightly  
on the lever1 when the propellant power 

drives it back   again4 ,the balance    
passes through two turns before the     
second locking   takes place1 and is    
formed so as to be able to take up the  
lever1   and the watch soon rights      
itself1 and its time will not be        
affected4   ,another advantage is1 that 
the lever is made of a flat piece of    
steel1   as ,i have introduced a gold   
stud to receive the ruby impulse stone1 
which is made to adjust easily so as to 
bring the escapement to the   closest   
geometrical accuracy4 ,by its formation 
this ruby guides the   impulse to the   
external edge of the roller notch4      
,these advantages1   and its simplicity1
 render it suitable to the best         
chronometer   watches40    ,a ,,few     
years ago1 in #ahei or '#fj1 ,mr4       
,peabody1 a very talented  gentleman of 
this city1 patented a three-pin         
escapement that performed  extremely    
well4 ,a full description of his patent 
and plan is not at  hand1 but we will   
endeavor to give it to our readers in   

our next issue4          ,english       
,opinion of ,american ,watch            
,manufacture4      ,in the ,london      
circle of ,horologists1 more attention  
is paid to the  scientific departments  
than the mercantile2 but for all that1 a
 ,mr4  ,henry ,ganney has held forth    
before the 8,british ,horological       
,institute10  on 8,american ,watch      
,manufacture40 ,though an ,englishman1  
with ,english  prejudices1 he certainly 
gives a very fair and impartial         
statement  of the subject2 yet he views 
it almost entirely in the money-making  
aspect4 ,he gives all the credit        
deserved to ,american enterprise and    
ingenuity1 and yet there is a certain   
sense of a drawback4 ,he had  before him
 samples of machine work2 among others1 
to quote1 8several  movements made by   
the ,british ,watch ,company1 which     
flourished and  failed about twenty-five
 years ago2 these were machine-made1 and
 the  perfection and completeness of the
 machinery they used for producing      

these frames has not been equalled1 ,i  
believe1 in ,america2 several  machines 
being used there to accomplish what was 
begun and completed by  one here40      
,mr4 ,ganney is right in his statement1 
but the example given by the  ,british  
,watch ,company was the rock seen by the
 ,american navigators4 ,one  tool1 for  
facing off1 truing up1 drilling1        
depthing1 and doing all the  work on the
 pillar plate1 having cost1 before      
completion1 some three  thousand pounds 
sterling1 and from its very complexity  
being utterly  inefficient--worse than  
useless4 ,in the very inception of the  
,american  watch manufacture a similar  
mistake was almost made4 ,experience and
  sound reasoning proved1 however1 that 
a multiplicity of operations in  any one
 machine rendered it entirely too       
complex1 the adjustments too  numerous1 
and the work totally worthless4 ,we     
shall in another number  refer again to 
,mr4 ,ganney's lecture1 and perhaps give
 some beamings of  light on the early   

history of the ,american watch          
manufacture1 derived  from personal     
observation at the time4                
,correspondence4        ,,editors       
,,horological ,,journal3     ,i received
 a ,prospectus a few days ago advising  
me of your   contemplated existence4 ,i 
could hardly believe the fact2 8the news
   was too good to be true40 ,however1  
,i shall take it for granted1 for ,i    
cannot see why somebody has not before  
had the enterprise to launch   out in   
the periodical line on subjects         
connected with ,horology1 the   field   
being so extensive and the want so      
severely felt4 ,enclosed   ,i send you  
the subscription price2 in this much ,i 
have accepted   your invitation1 but ,i 
also enclose some few lines on a subject
 not   particularly practical or        
theoretical1 but very near the truth1   
and   may perhaps give you a view of our
 wants4     ,to tell the 8plain         
unvarnished truth10 ,i am a watch       
repairer1 located   in a small country  

village1 with a decent stock of tools   
and a   moderate trade4 ,in all this ,i 
am no exception2 so ,i write this in    
the name of all who are similarly       
situated4 ,isolated as we are1 we   7the
 country village watch repairers7 have  
few means to improve our   knowledge of 
the trade1 but work on the same old     
principles learned   when we were boys  
and apprentices1 and of better and more 
expeditious   ways of doing our work we 
are entirely oblivious4 ,true1 our      
friends   of the ,hebraic persuasion1   
who1 angel like1 bring us face to face  
with the outer horological world by     
selling us material and tools1          
occasionally present to our benumbed    
vision something new1 such as a   ,swiss
 lathe1 or lathes used in the factories2
 but of what use are they   to us8 ,we  
purchase one2 well1 on the bench it may 
be an ornament1 but   for use1 drilling 
large holes is the height of our        
ambition4 ,we have   not the time to    
learn by self-experience all the boasted

 usefulness   and capacities of the     
tool2 so we go back to our old verge or 
,jacot   lathe when we have to put in a 
pivot or a new staff4 ,we may know all  
about the escapement and be able to     
detect the cause of any trouble   with  
it1 but we have no knowledge of the     
latest modes of repairing the   injury  
when it is discovered1 and this         
knowledge is what ,i hope to   find in  
your journal4 ,i live in a section where
 the general class of   work is of a    
very low grade1 even the old verge being
 very common4 ,our   stock of material  
has to be heavy in proportion to our    
trade1 and then   once in a while we are
 compelled to send our work to the city1
 some   sixty miles distant1 in         
consequence of not being able to do it1 
either   from a lack of the material or 
want of a proper tool4 ,to all intents  
and purposes we remain as stationary as 
the oyster4 ,not only do we   have these
 vexations1 but the ignorance of the    
public at large as to   the treatment of

 their time-keepers is a fruitful source
 of annoyance2   we are often charged   
with fraudulent practices1 and a certain
 degree   of caution is observed by more
 than the most ignorant4 ,thus1 a few   
days ago1 a stalwart son of the ,green  
,isle made his appearance in   front of 
the counter1 and1 projecting in front of
 our optics a huge   ,english           
double-cased verge watch1 spoke in      
almost dramatic tones3     8,plase1 sir1
 av' ye could make me ticker here go1   
sir80     ,answering in the affirmative 
we reached for the silent 8ticker40 ,he 
drew back with alarm4     8,bedad1 an'  
ye'll not stale a morsle frae this80    
8,well1 but let me see the watch40      
8,an' will ye let me eyes be on yes all 
the time80     8,yes40     8,an' yes'll 
not stale a jewil80     8,no40          
8,thin1 there it is40     ,on looking at
 the movement the verge was found       
broken1 the injury   explained1 and the 
price given4 ,he decided on the repairs 
being done1   but said1 8,give me the   

watch now and when ye gets the thing    
fixed its   meself will come and git it 
and pay yes40     8,but we cannot repair
 the watch without having it40          
8,faith1 thin1 ye'll not have it2 ye'll 
be taking something frae it40     ,now1 
this is an extreme case of ignorance1   
pardonable1 perhaps1 in   this instance1
 but the public embraces multitudes just
 as ignorant   where an allowance cannot
 be made4 ,i do not expect the ,,journal
 to   reach such cases1 or to influence 
the general mass1 but my hope is   that 
it will1 by raising the general         
self-respect and tone of the            
repairers1 indirectly elevate the       
respect felt for them by the public   at
 large4     ,but ,i am writing too long 
and rambling a letter4 ,i wish to       
express my   hearty wishes for your     
prosperity4 ,and1 in conclusion1 will   
you allow   me to express a hope that   
you will give us the knowledge we       
need--that   is1 post us up on the      
minuti of repairing in the latest       

styles1 the   newest processes devised1 
and1 above all1 give us an article on   
the   lathe and its uses8      ,yours   
truly1    ,w4 ,l4 ,c4      ,we have the 
pleasure to give our correspondent the  
assurance that an  expert will          
contribute to our next number an article
 interesting as  well as valuable in    
instruction as to the use of the lathe4 
,eclipse of the ,sun4      ,the         
approaching total eclipse of the sun1 on
 the #gth of ,august next1  is exciting 
much interest4 ,the obscuration first   
occurs in latitude  #ci #ec #c north1   
longitude #ach #cg #d west--,washington 
being the  meridian4 ,the first totality
 is on the ,pacific coast of ,siberia1  
at  sunrise1 in lat4 #eb #da #i north1  
and long4 #afe #bf #d west4 ,the        
eclipse is total at noon in ,alaska1    
lat4 #fa #df #i north1 and long4  #fh #d
 #f west4 ,the line of the total eclipse
 now runs south-easterly1  grazing the  
coast near ,sitka1 thence north into    
,british ,america2 then  entering the   

,united ,states1 near the head of ,milk 
,river1 long4 #cj ,w42  thence through  
the south-west corner of ,minnesota1    
diagonally through  ,iowa1 crosses the  
,mississippi at ,burlington2 thence     
through ,illinois1  a little north of   
,springfield1 crosses the ,ohio river at
 or near  ,louisville1 ,ky41 passes     
through the south-west corner of ,west  
,virginia1  through ,north ,carolina1   
just south of ,raleigh1 ending on the   
,atlantic  coast at sunset1 just north  
of ,beaufort1 ,n4 ,c41 in lat4 #ca #ae  
#b  north1 and long4 #i #cf #f east4    
,the line thus described will be that   
of totality1 only partial in any other  
part of the ,united ,states4    ,the    
,united ,states ,government is1 or has  
been1 establishing a meridian  line at  
,springfield1 partly to make            
observations on this coming  eclipse1   
and with the further view of determining
 a standard of  surveyed lines--all of  
the ,government surveys in ,illinois    
having been  geodetic4 ,professor       

,austin1 of the ,smithsonian ,institute1
 is in charge  of the work1 aided by an 
able corps of assistants4               
,diamond-,cutting4      ,at the ,great  
,exhibition in ,paris1 in a part of the 
park contiguous to  the ,netherland     
section1 ,m4 ,coster1 of ,amsterdam1 has
 erected a building  wherein all the    
processes of diamond-cutting are carried
 on4    ,the first rough shaping of the 
more important facets of the brilliants 
is here seen performed by the workman1  
who operates on two diamonds at  once1  
by bruising each against the other1     
angle against angle4 ,the dust  that    
falls from the stones is preserved for  
the subsequent processes  of grinding   
and polishing those facets that         
distinguish the many-sided  brilliant   
from the dull1 original crystal of the  
diamond4 ,it is used1  mingled with oil1
 on a flat iron disk1 set revolving with
 vast rapidity  by steam-power1 the     
stone itself being held upon this disk  
or wheel by  a tool to which it is      

attached by a mass of fusible metallic  
alloy1  into which the stone is         
skilfully inserted4 ,skill of eye and   
hand1 only  attainable by great         
practice1 is needed for this work2 but a
 skill not  less exact is needed for    
another process1 which may here be seen 
in  daily operation--the process of     
cleavage4 ,the diamond1 when a blow is  
struck on an edged tool placed parallel 
to one of the octahedral faces  of the  
crystal1 readily splits in that         
direction4 ,but to recognize the        
precise direction on the complex and    
generally rounded form of the  diamond  
crystal2 to cut a little notch by means 
of a knife edge of  diamonds formed of  
one of the slices cleaved from a        
crystal1 and to  cut that notch exactly 
the right spot2 then to plant the steel 
knife  that is to split the diamond     
precisely in the right position2        
finally1  with a smart blow1 to effect  
the cleavage so as to separate neither  
too large nor small a portion of the    

stone--these various steps in the       
process need great skill and judgment1  
and present to the observer  the        
interesting spectacle which a handicraft
 dependent on experience  of hand and   
eye always affords4 ,but ,mr4 ,coster's 
exhibition has other  objects of        
interest4 ,for the first time1 we may   
see here1 side by side1  the diamond    
with the minerals that accompany it in  
the river beds of  ,brazil2 and there   
are even examples in which crystals of  
diamonds  are included within a mass of 
quartz crystals1 which have all the     
appearance of having been formed        
simultaneously with deposits of the     
diamond4    ,the different districts of 
,rio and of ,bahia are thus             
represented--the  former producing a    
confusedly crystallized sort of diamond 
termed  8bort10 and the latter an opaque
 black variety2 both these kinds being  
found associated with the crystallized  
diamonds used for jewelry4  ,though     
useful in state of powder1 the black    

carbon and 8bort0 are  incapable of     
being cut as a jewel4--8,maskelyne's    
,report10 ,great  ,exhibition4          
,the ,alloys of ,aluminum with ,copper4 
,when ,sir ,humphrey ,davy announced the
 fact that soda1 lime1 potash1          
magnesia1 and the other alkalies were   
but oxides of a metallic base1 it  would
 have been deemed chimerical to have    
supposed that the discoveries  he made  
by the expensive aid of the battery     
would at later date become  of really   
commercial value4 ,he did obtain both   
sodium and potassium  in the metallic   
state4 ,the substances in this form were
 new to the  chemical world1 still more 
strange to the popular4 ,so new was it  
to the  chemists1 that1 on a globule of 
the reduced sodium being presented to  a
 very distinguished chemist1 he1 with   
some enthusiasm1 examined it2  and1     
admitting the fact of its being a metal1
 exclaimed1 8how heavy  it is60--when   
the real fact was that its specific     
gravity was less  than water2 the       

expression was the result of the general
 preconceived  opinion that a high      
specific gravity was a test of a        
metallic body4 ,it  was reserved for a  
,french chemist1 ,henry ,st4 ,claire    
,deville1 to utilize  the metal sodium1 
and that1 too1 in such a manner that the
 demand  aroused attention to its       
production2--demand will inevitably     
bring a  supply4    ,the original       
reduction was made by ,davy1 by means of
 the voltaic  battery4 ,after it had    
been proved that these bases were really
 metals  capable of reduction1 chemistry
 brought all its resources to bear on   
the problem1 and they were produced by  
other methods than the battery4  ,all   
the processes adopted1 however1 were too
 expensive and laborious1  involving an 
extraordinary amount of complicated     
manipulations with but  inadequate      
results4 ,the metal sodium1 which is the
 immediate subject of  our inquiry1 long
 remained an object simply of curiosity 
or experiment  in the laboratory4       

,the methods of reducing the metal have 
of late years been so simplified  that1 
to quote ,prof4 ,chas4 ,a4 ,joy in the  
,journal of ,applied  ,chemistry3 8,a   
few years ago a pound of this metal     
could not have been  purchased for two  
hundred dollars1 and even at that price 
there were  few manufacturers hardy     
enough to take the order4 ,at the       
present time  it can be readily         
manufactured for seventy-five cents1 if 
not for fifty  cents a pound2 and the   
probabilities are that we shall soon be 
able to  obtain it for one-quarter of a 
dollar40    ,deville found that by the  
reaction of the metallic sodium on      
common  chloride of aluminum a reduction
 was effected2 the chlorine taking  up  
the sodium1 forming chloride of sodium  
7common salt71 while the  aluminum was  
left free in the metallic state4 ,it is 
hardly necessary  to go into the        
particulars of the process2 but a metal 
well known to  exist1 had1 for the first
 time1 been brought to the world in such

 a  condition of structure that its     
qualities could be tested1 not only     
chemically1 but mechanically4 ,this was 
the direct result of ,deville's         
metallurgic process of obtaining the    
reducing agent--sodium4    ,aluminum in 
itself would be of but little use1 so   
that a brief  description will be all   
that is necessary4 ,it is about the     
color of  silver1 but susceptible of a  
higher polish1 especially on a fresh-cut
  surface2 it is much less susceptible  
of oxidization than silver2 its         
specific gravity is but little more than
 pine wood1 and its tenacity1           
ductility1 and laminating qualities are 
nearly equal to silver4 ,its use  in the
 mechanical arts is limited1            
notwithstanding all these qualities1    
from the fact of its low point of       
fusibility1 and at the heat of  the     
fusible point being easily oxidized1 so 
much so as to prevent  soldering1 except
 by an autogenous process4 ,but aluminum
 does possess  a property peculiar to   

itself--that of forming a purely and    
strictly  chemical alloy with copper4   
,it unites with it in any proportion2   
the compound formed by the addition of  
#aj per cent4 of aluminum to #ij  per   
cent4 of copper has been found to       
possess all the properties of  an       
entirely new metal1 with qualities that 
render it a very valuable  material in  
all fine work1 such as astronomical     
instruments2 and very  fine machinery1  
such as watch-lathes1 etc4    ,the      
,french reports on the alloy are        
somewhat voluminous1 but we give  the   
following4    ,the color of this bronze 
so closely resembles that of #ah carat  
gold1  such as is used for the best     
jewelry and watch-cases1 that it is     
capable of receiving the highest polish1
 and is far superior in beauty  to any  
gilding4    ,samples taken from         
different parts of the largest castings1
 when  analyzed1 show the most complete 
uniformity of composition1 provided     
only that the two metals have originally

 been properly mixed while in  a state  
of fusion4 ,these experiments have been 
made upon cylinders  weighing many      
hundreds of pounds1 and are entirely    
conclusive4    ,this valuable quality is
 not found in any of the more ordinary  
alloys  of copper4 ,the alloy of copper 
with tin1 for example1 known as gun     
metal1 is notoriously subject to a      
phenomenon known as liquation2  in      
consequence of which a great difference 
is found in the composition  of the same
 casting1 both in the top as compared   
with the bottom1 and  in the centre as  
compared with the circumference4        
,this phenomenon often causes great     
inconvenience1 as the different  parts  
of large objects will in consequence    
vary greatly in hardness  as well as in 
strength4 ,in casting artillery the     
difficulty becomes a  serious one1 and  
no means have yet been discovered by    
which it can be  entirely removed4      
,this homogeneousness of aluminum bronze
 is a natural consequence of the  great 

affinity existing between the two metals
 of which it is composed2  and that     
there is such an affinity is clearly    
proved by the phenomenon  attending the 
manufacture of the alloy4 ,the copper is
 first melted in  a crucible and the    
aluminum is then added to it in ingots4 
,at first  there is1 of course1 a       
reduction of temperature1 because the   
aluminum  in melting absorbs the heat   
from the melted copper2 and this        
absorption  is so great1 in consequence 
of the great capacity for heat of       
aluminum1  that a part of the copper may
 even become solid4 ,but let the mixture
  be stirred a moment with an iron bar1 
and the two metals immediately  unite2  
and in an instant1 although the crucible
 may have been removed  from the        
furnace1 the temperature of the metals  
rises to incandescence1  while the mass 
becomes as fluid as water4    ,this     
enormous disengagement of heat1 not seen
 in the preparation of  any other       
ordinary alloy1 indicates1 not a simple 

mixture1 but a real  chemical           
combination of the two metals4 ,the #aj 
per cent4 bronze may  therefore be      
properly compared to a salt1 the more so
 as it is found by  calculation to      
contain1 within a very minute fraction1 
four equivalents  of copper to one      
equivalent of aluminum4    ,the #aj per 
cent4 bronze may be forged cold1 and    
becomes extremely dense  under the      
action of the hammer4 ,the blades of    
dessert-knives are thus  treated in     
order to give them the requisite        
hardness and elasticity4  ,but it has   
another valuable quality which is found 
in no other kind  of brass or bronze3 it
 may be forged hot1 as well as1 if not  
better  than the very best iron4 ,it    
thus becomes harder and more rigid1 and 
its fracture shows a grain similar to   
that of cast steel4 ,on account  of the 
hardness of the aluminum bronze1 rolling
 it into sheets would  be a tedious and 
expensive process1 were it not for this 
property of  being malleable at a red   

heat4 ,but it may in this manner be     
rolled into  sheets of any thickness or 
drawn into wire of any size4 ,it may    
also be  drawn into tubes of any        
dimension4    ,from several experiments 
made at different times at ,paris1 it   
appears  that the breaking weight of the
 cast bronze varies from #fe to #gj     
kilogrammes the square millimetre4 ,the 
same bronze drawn into wire  supported a
 weight of #ij kilogrammes the square   
millimetre4 ,the iron  used for         
suspension bridges1 tested in the same  
manner1 did not show an  average of more
 than #cj kilogrammes4 ,some experiments
 were also made by  ,mr4 ,anderson1 at  
the ,royal ,arsenal at ,woolwich1 in    
,england1 who tested  at the same time  
the aluminum bronze1 the brass used for 
artillery  and commonly called gun      
metal1 and the cast steel made by ,krupp
 in  ,prussia4 ,taking for the maximum  
strength of the bronze the lowest of    
the numbers found as above1 we are thus 
enabled to form the following  table of 

comparative tenacities3      ,aluminum  
bronze #aj per cent4       #fe          
,crupp's ,cast ,steel                   
#ec    ,refined ,iron                   
#cj    ,brass for cannon                
#bh    ,the comparative toughness of    
these same four metals was also tested  
in  the following manner3 ,a bar of each
 was prepared of the same size1 and     
each bar was then notched with a chisel 
to precisely the same depth4  ,the bars 
were broken separately1 upon an anvil1  
by blows from a hammer4  ,the last three
 metals in the table broke each at the  
first blow1 with  a clean and square    
fracture4 ,the aluminum bronze only     
began to crack  at the eighth blow1 and 
required a number of additional blows   
before  the two pieces were entirely    
separated4 ,and the irregular1 torn     
surface  of the fracture showed the     
peculiarly tough and fibrous nature of  
the  metal4    ,the elasticity of the   
aluminum bronze was tested by ,m4       
,tresca1  ,professor at the             

,conservatoire des ,arts et ,mtiers4    
,the experiment  was made upon a bar of 
simple cast metal1 and the following is 
his  report3 8,the coefficient of       
elasticity of the aluminum bronze1 the  
cast metal1 is half that of the best    
wrought-iron4 ,this coefficient is      
double that of brass and four times that
 of gun metal1 under the same           
conditions40    ,the specific gravity is
 #g4g1 about the same as iron4 ,another 
very  valuable quality is presented in  
the fact that it is acted on by         
atmospheric influences less than are    
silver1 brass1 or bronze4 ,this  places 
it in the same rank with gold1 platinum 
and aluminum4    ,very stiff and very   
elastic1 tougher than iron1 very little 
acted upon  chemically1 and in certain  
cases not at all1 capable of being cast 
like  ordinary bronze or brass1 forged  
like iron and steel1 of being worked  in
 every way like the most malleable      
metals or alloys1 having1 added  to     
these properties1 a color analogous to  

that of the most precious  metal1 this  
bronze proves itself adapted to uses    
almost innumerable4  ,at first sight1 it
 seems difficult to admit that the      
relatively small  proportions of        
aluminum which enters into the          
composition of this  bronze can be      
sufficient to modify so extraordinarily 
the properties  of the copper which     
constitutes so large a portion of its   
weight4 ,but  we must remember that the 
specific gravity of aluminum is very    
low1  and that a given weight of this   
metal possesses a bulk four times as    
large as the same weight in silver4 ,it 
follows from this that the ten  per     
cent4 of aluminum contained in the      
bronze equals in bulk forty per  cent4  
in silver4    ,the specimens of the ware
 we have seen1 such as spoons1 forks1   
cups1  watch-cases1 etc41 are certainly 
very beautiful1 having the color and    
high polish of gold1 while dilute acids 
do not affect the surface4          ,on 
the ,reduction of ,silver in the ,wet   

,way4      ,every chemist is familiar   
with the reduction of chloride of silver
  in the form of powder by means of     
metallic zinc in the presence of a      
little free acid4 ,it is not easy to    
bring two such substances as the  silver
 salt and the metal into close contact1 
and after the work is  accomplished the 
removal of the excess of zinc has its   
difficulties4  ,dr4 ,grager suggests a  
modification of the old method that     
ought to  be more generally made known4 
,the chloride of silver is dissolved  in
 ammonia and poured into a well-stopped 
bottle1 and into this is  introduced an 
excess of metallic zinc1 in not too     
small fragments1 so  that any reduced   
metal adhering to it may be readily     
washed off4    ,the decomposition begins
 immediately1 and is rapidly            
accomplished1  especially if the        
contents of the flask be well shaken up4
 ,three hours  will suffice to reduce   
one-quarter of a pound of chloride of   
silver4  ,it is easy to ascertain when  

the reduction is ended1 by testing a    
portion of the ammoniacal solution with 
hydrochloric acid4 ,as soon as  no      
cloudiness or curdy precipitate is      
formed1 the work may be regarded  as    
completed4    ,a slight excess of       
ammonia is said to be favorable4 ,the   
reduced silver  must be washed with     
water until all odor of ammonia has     
disappeared4  ,the pieces of zinc are   
removed by pouring the contents of the  
flask  through a funnel1 the opening of 
which is too narrow for the passage  of 
the zinc fragments1 while the reduced   
silver can be easily washed  through4   
,the finely divided silver can be       
digested in hydrochloric  acid to       
restore it to a pure white color1 and it
 is then ready for  solution or fusion1 
and will be found to be perfectly pure4 
,in dealing  with large quantities it   
would be economical to recover a portion
 of  the ammonia by distillation4 ,in   
the same way an ammoniacal solution  of 
nitrate of silver can also be reduced by

 zinc1 and the silver  obtained pure1   
even when the original solution of the  
nitrate contains  copper--provided a    
small quantity of silver be kept in the 
bath4    ,it is better where copper is  
present not to take all of the zinc that
  may be requisite for the reduction of 
the silver4 ,it will prove a  great     
convenience to be spared the necessity  
of converting the silver  into the      
chloride1 as it is no easy task to wash 
out this salt on  filters--and it will  
be found to be applicable to alloys     
which do not  contain more than #be per 
cent4 of silver4--,from ,prof4 ,joy in  
the  ,journal of ,applied ,chemistry4   
,transcriber's ,notes    ,obvious errors
 in punctuation have been fixed4        
,page #g3 8,mechanique ,celeste0 changed
 to 8,mchanique ,cleste0    ,page #ab3  
8ou rexperience0 changed to 8our        
experience0    ,page #ah3 8head-quarters
 far astronomical observations0 changed 
to  8head-quarters for astronomical     
observations0    ,page #bb3 8it         

accomodates0 changed to 8it             
accommodates0    ,the ,table of         
,contents lists 8,equation of the ,time 
,table0 as the article  on page #bh4    
,the actual article is named 8,on the   
,reduction of ,silver in  the ,wet      
,way40 ,this has intentionally been left
 as per the original4  ,similarly1 there
 is no actual section titled 8,notices  
of ,new ,tools0  despite its inclusion  
in the ,table of ,contents1 and this has
 been left  as per the original4