,transcriber's ,note3 ,all footnotes are grouped at the end of the file4 ,those that include non-bibliographic information are also shown after their referring paragraph4 ,this ,,utf-#h file includes a few less common fractions such as and 4 ,readers who cannot see these characters may prefer the ,latin-#a version of the file4 99 99 99 99 99 ,,american ,,society ,,of ,,civil ,,engineers ,instituted #aheb ,,transactions ,paper ,no4 #aaga ,,federal ,,investigations ,,of ,,mine ,,accidents1 ,,structural ,,materials1 ,,and ,,fuels4#a ,by ,,herbert ,m4 ,,wilson1 ,m4 ,am4 ,soc4 ,c4 ,e4 ,with ,discussion by ,messrs4 ,,kenneth ,,allen1 ,,henry ,,kreisinger1 ,,walter ,o4 ,,snelling1 ,a4 ,,bartoccini1 ,h4 ,g4 ,,stott1 ,b4 ,w4 ,,dunn1 and ,,herbert ,m4 ,,wilson4 ,,introduction4 ,the mine disaster1 which occurred at ,cherry1 ,ill41 on ,november #acth1 #aiji1 when #ebg men were in the mine1 resulting in the entombment of #ccj men1 of whom #caj were killed1 has again focused public attention on the frequent recurrence of such disasters and their appalling consequences4 ,interest in the possible prevention of such disasters1 and the possible means of combating subsequent mine fires and rescuing the imprisoned miners1 has been heightened as it was not even by the series of three equally extensive disasters which occurred in #aijg1 for the reason that1 after the ,cherry disaster1 #bj men were rescued alive after an entombment of one week1 when practically all hope of rescuing any of the miners had been abandoned4 ,this accident1 occurring1 as it does1 a little more than #a years after the enactment of legislation by ,congress instructing the ,director of the ,united ,states ,geological ,survey to investigate the causes and possible means of preventing the loss of life in coal-mining operations1 makes this an opportune time to review what has been done by the ,geological ,survey during this time1 toward carrying out the intent of this ,act4 ,it may be stated with confidence1 that had such a disaster occurred a year or more ago1 all the entombed men must have perished1 as it would have been impossible to enter the mine without the protection afforded by artificial respiratory apparatus4 ,moreover1 but for the presence of the skilled corps of ,government engineers1 experienced by more than a year's training in similar operations in more than twenty disasters1 the mine would have been sealed until the fire had burned out1 and neither the dead1 nor those who were found alive1 would have been recovered for many weeks4 ,in the interval great suffering and loss would have been inflicted on the miners1 because of enforced idleness1 and on the mine owners because of continued inability to re-open and resume operations4 ,character of the ,work4--,the ,united ,states ,geological ,survey has been engaged continuously since #aijd in conducting investigations relating to structural materials1 such as stone1 clay1 cement1 etc41 and in making tests and analyses of the coals1 lignites1 and other mineral fuel substances1 belonging to1 and for the use of1 the ,government4 ,incidentally1 the ,survey has been considering means to increase efficiency in the use of these resources as fuels and structural materials1 in the hope that the investigations will lead to their best utilization4 ,these inquiries attracted attention to the waste of human life incident to the mining of fuel and its preparation for the market1 with the result that1 in ,may1 #aijh1 provision was made by ,congress for investigations into the causes of mine explosions with a view to their prevention4 ,statistics collected by the ,geological ,survey show that the average death rate in the coal mines of the ,united ,states from accidents of all kinds1 including gas and dust explosions1 falls of roof1 powder explosions1 etc41 is three times that of ,france1 ,belgium1 or ,germany4 ,on the other hand1 in no country in the world are natural conditions so favorable for the safe extraction of coal as in the ,united ,states4 ,in ,belgium1 foremost in the study of mining conditions1 a constant reduction in the death rate has been secured1 and from a rate once nearly as great as that of the ,united ,states1 namely1 #c4bh per thousand1 in the period #ahea-fj1 it had been reduced to about #b per thousand in the period #ahha-ij2 and in the last decade this has been further reduced to nearly #a per thousand4 ,it seems certain1 from the investigations already made by the ,geological ,survey1 that better means of safeguarding the lives of miners will be found1 and that the death rate from mine accidents will soon show a marked reduction4 ,other statistics collected by the ,geological ,survey show that1 to the close of #aijg1 nearly #g1jjj1jjj1jjj tons of coal had been mined in the ,united ,states1 and it is estimated that for every ton mined nearly a ton has been wasted1 #c1ejj1jjj1jjj tons being left in the ground or thrown on the dump as of a grade too low for commercial use4 ,to the close of #aijg the production represents an exhaustion of somewhat more than #aj1jjj1jjj1jjj tons of coal4 ,it has been estimated that if the production continues to increase1 from the present annual output of approximately #dae1jjj1jjj tons1 at the rate which has prevailed during the last fifty years1 the greater part of the more accessible coal supply will be exhausted before the middle of the next century4 ,the ,forest ,service estimates that1 at the present rate of consumption1 renewals of growth not being taken into account1 the timber supply will be exhausted within the next quarter of a century4 ,it is desirable1 therefore1 that all information possible be gained regarding the most suitable substitutes for wood for building and engineering construction1 such as iron1 stone1 clay products1 concrete1 etc41 and that the minimum proportion in which these materials should be used for a given purpose1 be ascertained4 ,exhaustion1 by use in engineering and building construction1 applies not only to the iron ore1 clay1 and cement-making materials1 but1 in larger ratio1 to the fuel essential to rendering these substances available for materials of construction4 ,incidentally1 investigations into the waste of structural materials have developed the fact that the destructive losses1 due to fires in combustible buildings1 amount to more than #bjj1jjj1jjj per annum4 ,a sum even greater than this is annually expended on fire protection4 ,inquiries looking to the reduction of fire losses are being conducted in order to ascertain the most suitable fire-resisting materials for building construction4 ,early in #aijd1 during the ,louisiana ,purchase ,exposition1 ,congress made provision for tests1 demonstrations1 and investigations concerning the fuels and structural materials of the ,united ,states4 ,these investigations were organized subsequently as the ,technologic ,branch of the ,united ,states ,geological ,survey1 under ,mr4 ,joseph ,a4 ,holmes1 ,expert in ,charge1 and the ,president of the ,united ,states invited a group of civilian engineers and ,chiefs of ,engineering ,bureaus of the ,government to act as a ,national ,advisory ,board concerning the method of conducting this work1 with a view to making it of more immediate benefit to the ,government and to the people of the ,united ,states4 ,this ,society is formally represented on this ,board by ,c4 ,c4 ,schneider1 ,past-,president1 ,am4 ,soc4 ,c4 ,e41 and ,george ,s4 ,webster1 ,m4 ,am4 ,soc4 ,c4 ,e4 ,among representatives of other engineering societies1 or of ,government ,bureaus1 the membership of the ,national ,advisory ,board includes other members of this ,society1 as follows3 ,general ,william ,crozier1 ,frank ,t4 ,chambers1 ,professor ,w4 ,k4 ,hatt1 ,richard ,l4 ,humphrey1 ,robert ,w4 ,hunt1 ,h4 ,g4 ,kelley1 ,robert ,w4 ,lesley1 ,john ,b4 ,lober1 ,hunter ,mc,donald1 and ,frederick ,h4 ,newell4 ,in view1 therefore1 of the important part taken both officially and unofficially by members of this ,society in the planning and organization of this work1 it seems proper to present a statement of the scope1 methods1 and progress of these investigations4 ,whereas the ,act governing this work limits the testing and investigation of fuels and of structural materials to those belonging to the ,united ,states1 the activities of the ,federal ,government in the use of these materials so far exceeds that of any other single concern in the ,united ,states1 that the results cannot but be of great value to all engineers and to all those engaged in engineering works4 ,,mine ,,accidents ,,investigations4 ,organization1 and ,character of the ,work4--,the mine rescue investigations1 carried on at the ,federal testing station1 at ,pittsburg1 ,pa41 include five lines of attack3 #a4--;,investigations in the mines to determine the conditions leading up to mine disasters1 the presence and the relative explosibility of mine gas and coal dust1 and mine fires and means of preventing and combating them4 #b4--,tests to determine the relative safety1 or otherwise1 of the various explosives used in coal mining1 when ignited in the presence of explosible mixtures of natural gas and air1 or coal dust1 or of both4 #c4--,tests to determine the conditions under which electric equipment is safe in coal-mining operations4 #d4--,tests to determine the safety of various types of mine lights in the presence of inflammable gas1 and their accuracy in detecting small percentages of mine gas4 #e4--,tests of the various artificial breathing apparatus1 and the training of miners and of skilled mining engineers in rescue methods4 ,the first four of these lines of investigation have to do with preventive measures1 and are those on which ultimately the greatest dependence must be placed4 ,the fifth is one in which the result seems at first to be the most apparent4 ,it has to do1 not with prevention1 but with the cure of conditions which should not arise1 or1 at least1 should be greatly ameliorated4 ,during the last #ai years1 #bh1ead men have been killed in the coal-mining industries4#b ,in #aijg alone1 #c1abe men lost their lives in coal mines1 and1 in addition1 nearly #hjj were killed in the metal mines and quarries of the country4 ,including the injured1 #h1dda men suffered casualties in the mines in that year4 ,in every mining camp containing #a1jjj men1 #d4hf were taken by violent death in that year4 ,in the mining of coal in ,great ,britain1 #a4ca men were killed in every #a1jjj employed in the same year2 in ,france1 #a4a2 in ,belgium1 #j4id1 or less than #a man in every #a1jjj employed4 ,it is thus seen that from three to four times as many men are being killed in the ,united ,states as in any ,european coal-producing country4 ,this safer condition in ,europe has resulted from the use of safer explosives1 or the better use of the explosives available2 from the reduction in the use of open lights2 from the establishment of mine rescue stations and the training with artificial breathing apparatus2 and from the adoption of regulations for safeguarding the lives of the workmen4 ,the mining engineering field force of the ,geological ,survey1 at the head of which is ,mr4 ,george ,s4 ,rice1 an experienced mining and consulting engineer1 has already made great progress in the study of underground mining conditions and methods4 ,nearly all the more dangerous coal mines in the ,united ,states have been examined2 samples of gas1 coal1 and dust have been taken and analyzed at the chemical laboratories at ,pittsburg2 extended tests have been made as to the explosibility of various mixtures of gas and air2 as to the explosibility of dust from various typical coals2 as to the chemical composition and physical characteristics of this dust2 the degree of fineness necessary to the most explosive conditions2 and the methods of dampening the dust by water1 by humidifying1 by steam1 or of deadening its explosibility by the addition of calcium chloride1 stone dust1 etc4 ,a bulletin outlining the results thus far obtained in the study of the coal-dust problem is now in course of publication4#c ,after reviewing the history of observations and experiments with coal dust carried on in ,europe1 and later1 the experiments at the ,french1 ,german1 ,belgian1 and ,english explosives-testing stations1 this bulletin takes up the coal-dust question in the ,united ,states4 ,further chapters concern the tests as to the explosibility of coal dust1 made by the ,geological ,survey1 at ,pittsburg2 investigations1 both at the ,pittsburg laboratory and in mines1 as to the humidity of mine air4 ,there is also a chapter on the chemical investigations into the ignition of coal dust by ,dr4 ,j4 ,c4 ,w4 ,frazer1 of the ,geological ,survey4 ,the application of some of these data to actual mine conditions in ,europe1 in the last year1 is treated by ,mr4 ,axel ,larsen2 the use of exhaust steam in a mine of the ,consolidation ,coal ,company1 in ,west ,virginia1 is discussed by ,mr4 ,frank ,haas1 ,consulting ,engineer2 and the use of sprays in ,oklahoma coal mines is the subject of a chapter by ,mr4 ,carl ,scholz1 ,vice-,president of the ,rock ,island ,coal ,mining ,company4 ,an earlier bulletin setting forth the literature and certain mine investigations of explosive gases and dust1#d has already been issued4 ,after treating of methods of collecting and analyzing the gases found in mines1 of investigations as to the rate of liberation of gas from coal1 and of studies on coal dust1 this bulletin discusses such factors as the restraining influence of shale dust and dampness on coal-dust explosions4 ,it then takes up practical considerations as to the danger of explosions1 including the relative inflammability of old and fresh coal dust4 ,the problems involved are undergoing further investigation and elaboration1 in the light of information already gathered4 ,permissible ,explosives4--,the most important progress in these tests and investigations has been made in those relating to the various explosives used in getting coal from mines4 ,immediately upon the enactment of the first legislation1 in the spring of #aijh1 arrangements were perfected whereby the lower portion of the old ,arsenal grounds belonging to the ,war ,department and adjacent to the ,pennsylvania ,railroad1 on the ,alleghany ,river1 at #djth and ,butler ,streets1 ,pittsburg1 ,pa41 were transferred to the ,interior ,department for use in these investigations4 ,meantime1 in anticipation of the appropriation1 ,mr4 ,clarence ,hall1 an engineer experienced in the manufacture and use of explosives1 was sent to ,europe to study the methods of testing explosives practiced at the ,government stations in ,great ,britain1 ,germany1 ,belgium1 and ,france4 ,mr4 ,joseph ,a4 ,holmes also visited ,europe for the purpose of studying methods of ameliorating conditions in the mines4 ,three foreign mining experts1 the chiefs of investigating bureaus in ,belgium1 ,germany1 and ,england1 spent three months studying conditions in the ,united ,states at the invitation of the ,secretary of the ,interior1 to whom they submitted a valuable report4#e ,under the supervision of the writer1 ,chief ,engineer of these investigations1 detailed plans and specifications had been prepared in advance for the necessary apparatus and the transformation of the buildings at ,pittsburg to the purposes of this work4 ,it was possible1 therefore1 to undertake immediately the changes in existing buildings1 the erection of new buildings1 the installation of railway tracks1 laboratories1 and the plumbing1 heating1 and lighting plant1 etc4 ,this work was carried on with unusual expedition1 under the direction of the ,assistant ,chief ,engineer1 ,mr4 ,james ,c4 ,roberts1 and was completed within a few months1 by which time most of the apparatus was delivered and installed4 ,one building 7,no4 #ag7 is devoted to the smaller physical tests of explosives4 ,it was rendered fire resistant by heavily covering the floors1 ceiling1 and walls with cement on metal lath1 and otherwise protecting the openings4 ,in it are installed apparatus for determining calorific value of explosives1 pressure produced on ignition1 susceptibility to ignition when dropped1 rate of detonation1 length and duration of flame1 and kindred factors4 ,elsewhere on the grounds is a gallery of boiler-steel plate1 #ajj ft4 long and more than #f ft4 in diameter1 solidly attached to a mass of concrete at one end1 in which is embedded a cannon from which to discharge the explosive under test1 and open at the other end1 and otherwise so constructed as to simulate a small section of a mine gallery 7,fig4 #b1 ,plate ,,vi74 ,the heavy mortar pendulum1 for the pendulum test for determining the force produced by an explosive1 is near by1 as is also an armored pit in which large quantities of explosive may be detonated1 with a view to studying the effects of magazine explosions1 and for testing as to the rate at which ignition of an explosive travels from one end to the other of a cartridge1 and the sensitiveness of one cartridge to explosion by discharge of another near by4 ,illustration3 ,,plate ,,vi4 ,fig4 #a4--;,explosion from ,coal ,dust in ,gas and ,dust ,gallery ,no4 #a4 ,fig4 #b4--,mine ,gallery ,no4 #a4 ,fig4 #c4--;,ballistic ,pendulum4 ,in another building 7,no4 #ba71 is a well-equipped chemical laboratory for chemical analyses and investigations of explosives1 structural materials1 and fuels4 ,several months were required to calibrate the various apparatus1 and to make analyses of the available natural gas to determine the correct method of proportioning it with air1 so as to produce exact mixtures of #b1 #d1 #f1 or #h of methane with air4 ,tests of existing explosives were made in air and in inflammable mixtures of air and gas1 with a view to fixing on some standard explosive as a basis of comparison4 ,ultimately1 #dj nitro-glycerine dynamite was adopted as the standard4 ,investigative tests having been made1 and the various factors concerning all the explosives on the market having been determined1 a circular was sent to all manufacturers of explosives in the ,united ,states1 on ,january #ith1 #aiji1 and was also published in the various technical journals1 through the associated press1 and otherwise4 ,on ,may #aeth1 #aiji1 all the explosives which had been offered for test1 as permissible1 having been tested1 the first list of permissible explosives was issued1 as given in the following circular3 8,,explosives ,,circular ,,no4 #a4 8,,department ,,of ,,the ,,interior4 8,united ,states ,geological ,survey4 8,may #ae1 #aiji4 8,,list ,,of ,,permissible ,,explosives4 8,tested prior to ,may #ae1 #aiji4 8,as a part of the investigation of mine explosions authorized by ,congress in ,may1 #aijh1 it was decided by the ,secretary of the ,interior that a careful examination should be made of the various explosives used in mining operations1 with a view to determining the extent to which the use of such explosives might be responsible for the occurrence of these disasters4 8,the preliminary investigation showed the necessity of subjecting to rigid tests all explosives intended for use in mines where either gas or dry inflammable dust is present in quantity or under conditions which are indicative of danger4 8,with this in view1 a letter was sent by the ,director of the ,united ,states ,geological ,survey on ,january #i1 #aiji1 to the manufacturers of explosives in the ,united ,states1 setting forth the conditions under which these explosives would be examined and the nature of the tests to which they would be subjected4 8,inasmuch as the conditions and tests described in this letter were subsequently followed in testing the explosives given in the list below1 they are here reproduced1 as follows3 87#a7 ,the manufacturer is to furnish #ajj pounds of each explosive which he desires to have tested2 he is to be responsible for the care1 handling1 and delivery of this material at the testing station on the ,united ,states arsenal grounds1 ,fortieth and ,butler streets1 ,pittsburg1 ,pa41 at the time the explosive is to be tested2 and he is to have a representative present during the tests1 who will be responsible for the handling of the packages containing the explosives until they are opened for testing4 87#b7 ,no one is to be present at or to participate in these tests except the necessary government officers at the testing station1 their assistants1 and the representative of the manufacturer of the explosives to be tested4 87#c7 ,the tests will be made in the order of the receipt of the applications for them1 provided the necessary quantity of the explosive is delivered at the plant by the time assigned1 of which due notice will be given by the ,geological ,survey4 87#d7 ,preference will be given to the testing of explosives that are now being manufactured and that are in that sense already on the market4 ,no test will be made of any new explosive which is not now being manufactured and marketed1 until all explosives now on the market that may be offered for testing have been tested4 87#e7 ,a list of the explosives which pass certain requirements satisfactorily will be furnished to the state mine inspectors1 and will be made public in such further manner as may be considered desirable4 8,,test ,,requirements ,,for ,,explosives4 8,the tests will be made by the engineers of the ,united ,states ,explosives ,testing ,station at ,pittsburg1 ,pa41 in gas and dust gallery ,no4 #a4 ,the charge of explosive to be fired in tests #a1 #b1 and #c shall be equal in disruptive power to one-half pound 7#bbg grams7 of #dj per cent4 nitroglycerin dynamite in its original wrapper1 of the following formula3 ,nitroglycerin #dj ,nitrate of sodium #dd ,wood pulp #ae ,calcium carbonate #a --- #ajj 8,each charge shall be fired with an electric fuse of sufficient power to completely detonate or explode the charge1 as recommended by the manufacturer4 ,the explosive must be in such condition that the chemical and physical tests do not show any unfavorable results4 ,the explosives in which the charge used is less than #ajj grams 7#j4bb pound7 will be weighed in tinfoil without the original wrapper4 8,the dust used in tests #b1 #c1 and #d will be of the same degree of fineness and taken from one mine4#f ,footnote #f3 ,with a view to obtaining a dust of uniform purity and inflammability4 8,,test #a4--,ten shots with the charge as described above1 in its original wrapper1 shall be fired1 each with #a pound of clay tamping1 at a gallery temperature of #gg ,f41 into a mixture of gas and air containing #h per cent4 of methane and ethane4 ,an explosive will pass this test if all ten shots fail to ignite the mixture4 8,,test #b4--,ten shots with charge as previously noted1 in its original wrapper1 shall be fired1 each with #a pound of clay tamping at a gallery temperature of #gg ,f41 into a mixture of gas and air containing #d per cent4 of methane and ethane and #bj pounds of bituminous coal dust1 #ah pounds of which is to be placed on shelves laterally arranged along the first #bj feet of the gallery1 and #b pounds to be placed near the inlet of the mixing system in such a manner that all or part of it will be suspended in the first division of the gallery4 ,an explosive will pass this test if all ten shots fail to ignite the mixture4 8,,test #c4--,ten shots with charge as previously noted1 in its original wrapper1 shall be fired1 each with #a pound of clay tamping at a gallery temperature of #gg ,f41 into #dj pounds of bituminous coal dust1 #bj pounds of which is to be distributed uniformly on a horse placed in front of the cannon and #bj pounds placed on side shelves in sections #d1 #e1 and #f4 ,an explosive will pass this test if all ten shots fail to ignite the mixture4 8,,test #d4--;,a limit charge will be determined within #be grams by firing charges in their original wrappers1 untamped1 at a gallery temperature of #gg ,f41 into a mixture of gas and air containing #d per cent4 of methane and ethane and #bj pounds of bituminous coal dust1 to be arranged in the same manner as in test #b4 ,this limit charge is to be repeated five times under the same conditions before being established4 8,,note4--,at least #b pounds of clay tamping will be used with slow-burning explosives4 8,washington1 ,d4,c41 ,january #i1 #aiji4 8,in response to the above communication applications were received from #ab manufacturers for the testing of #bi explosives4 ,of these explosives1 the #ag given in the following list have passed all the test requirements set forth1 and will be termed permissible explosives4 8,permissible explosives tested prior to ,may #ae1 #aiji4 ---------------------------------------- ---------------------------- ,brand4 ,manufacturer4 ---------------------------------------- ---------------------------- tna coal powder ,a tna ,powder ,co41 ,chicago1 ,ill4 tna coal powder ,b ,do4 ,carbonite ,no4 #a ,e4 ,i4 ,dupont de ,nemours ,powder ,co41 ,wilmington1 ,del4 ,carbonite ,no4 #b ,e4 ,i4 ,du ,pont de ,nemours ,powder ,co41 ,wilmington1 ,del4 ,carbonite ,no4 #c ,do4 ,carbonite ,no4 #a ,l4 ,f4 ,do4 ,carbonite ,no4 #b ,l4 ,f4 ,do4 ,coal special ,no4 #a ,keystone ,powder ,co41 ,emporium1 ,pa4 ,coal special ,no4 #b ,do4 ,coalite ,no4 #a ,potts ,powder ,co41 ,new ,york ,city4 ,coalite ,no4 #b ,d ,do4 ,collier dynamite ,no4 #b ,sinnamahoning ,powder ,co41 ,emporium1 ,pa4 ,collier dynamite ,no4 #d ,do4 ,collier dynamite ,no4 #e ,do4 ,masurite ,m4 ,l4 ,f4 ,masurite ,explosive ,co41 ,sharon1 ,pa4 ,meteor dynamite ,e4 ,i4 ,du ,pont de ,nemours ,powder ,co41 ,wilmington1 ,del4 ,monobel ,do4 ---------------------------------------- ---------------------------- 8,subject to the conditions named below1 a permissible explosive is defined as an explosive which has passed gas and dust gallery tests ,nos4 #a1 #b1 and #c as described above1 and of which in test ,no4 #d #a pounds 7#fhj grams7 of the explosive has been fired into the mixture there described without causing an ignition4 8,provided3 8#a4 ,that the explosive is in all respects similar to the sample submitted by the manufacturer for test4 8#b4 ,that double-strength detonators are used of not less strength than #a gram charge consisting by weight of #ij parts of mercury fulminate and #aj parts of potassium chlorate 7or its equivalent71 except for the explosive #8,masurite ,m4 ,l4 ,f4' for which the detonator shall be of not less strength than #a grams charge4 8#c4 ,that the explosive1 if in a frozen condition1 shall be thoroughly thawed in a safe and suitable manner before use4 8#d4 ,that the amount used in practice does not exceed #a pounds 7#fhj grams7 properly tamped4 8,the above partial list includes the permissible explosives that have passed these tests prior to ,may #ae1 #aiji4 ,the announcement of the passing of like tests by other explosives will be made public immediately after the completion of the tests for such explosives4 8,a description of the method followed in making these and the many additional tests to which each explosive is subjected1 together with the full data obtained in each case1 will be published by the ,survey at an early date4 8,,notes ,,and ,,suggestions4 8,it may be wise to point out in this connection certain differences between the permissible explosives as a class and the black powders now so generally used in coal mining1 as follows3 87a7 ,with equal quantities of each1 the flame of the black powder is more than three times as long and has a duration three thousand to more than four thousand times that of one of the permissible explosives1 also the rate of explosion is slower4 87b7 ,the permissible explosives are one and one-fourth to one and three-fourths times as strong and are said1 if properly used1 to do twice the work of black powder in bringing down coal2 hence only half the quantity need be used4 87c7 ,with #a pound of a permissible explosive or #b pounds of black powder1 the quantity of noxious gases given off from a shot averages approximately the same1 the quantity from the black powder being less than from some of the permissible explosives and slightly greater than from others4 ,the time elapsing after firing before the miner returns to the working face or fires another shot should not be less for permissible explosives than for black powder4 8,the use of permissible explosives should be considered as supplemental to and not as a substitute for other safety precautions in mines where gas or inflammable coal dust is present under conditions indicative of danger4 ,as stated above1 they should be used with strong detonators2 and the charge used in practice should not exceed #a pounds1 and in many cases need not exceed #a pound4 8,inasmuch as no explosive manufactured for use in mining is flameless1 and as no such explosive is entirely safe under all the variable mining conditions1 the use of the terms #8flameless' and #8safety' as applied to explosives is likely to be misunderstood1 may endanger human life1 and should be discouraged4 8,,joseph ,a4 ,,holmes1 8,expert in ,charge ,technologic ,branch4 8,approved1 ,may #ah1 #aiji3 8,,geo4 ,,otis ,,smith1 8,director40 ,in the meantime1 many of the explosives submitted1 which heretofore had been on the market as safety explosives1 were found to be unsafe for use in gaseous or dusty mines1 and the manufacturers were permitted to withdraw them4 ,their weaknesses being known1 as a result of these tests1 the manufacturers were enabled to produce similar1 but safer1 explosives4 ,consequently1 applications for further tests continued to pour in1 as they still do1 and on ,october #ast1 #aiji1 a second list of permissible explosives was issued1 as follows3 8,,explosives ,,circular ,,no4 #b4 8,,department ,,of ,,the ,,interior4 8,united ,states ,geological ,survey4 8,october #a1 #aiji4 8,,list ,,of ,,permissible ,,explosives4 8,tested prior to ,october #a1 #aiji4 8,the following list of permissible explosives tested by the ,united ,states ,geological ,survey at ,pittsburg1 ,pa41 is hereby published for the benefit of operators1 mine owners1 mine inspectors1 miners1 and others interested4 8,the conditions and test requirements described in ,explosives ,circular ,no4 #a1 issued under date of ,may #ae1 #aiji1 have been followed in all subsequent tests4 8,subject to the provisions named below1 a permissible explosive is defined as an explosive which is in such condition that the chemical and physical tests do not show any unfavorable results2 which has passed gas and dust gallery tests ,nos4 #a and #c1 as described in circular ,no4 #a2 and of which1 in test ,no4 #d1 #a pounds 7#fhj grams7 has been fired into the mixture there described without causing ignition4 8,permissible explosives tested prior to ,october #a1 #aiji4 8,those reported in ,explosives ,circular ,no4 #a are marked 994 ---------------------------------------- --------------------------- ,brand4 ,manufacturer4 ---------------------------------------- --------------------------- 99tna coal powder ,a tna ,powder ,co41 ,chicago1 ,ill4 tna coal powder ,,aa ,do4 99tna coal powder ,b ,do4 tna coal powder ,c ,do4 ,bituminite ,no4 #a ,jefferson ,powder ,co41 ,birmingham1 ,ala4 ,black ,diamond ,no4 #c ,illinois ,powder ,manufacturing ,co41 ,st4 ,louis1 ,mo4 ,black ,diamond ,no4 #d ,do4 99,carbonite ,no4 #a ,e4 ,i4 ,du ,pont de ,nemours ,powder ,co41 ,wilmington1 ,del4 99,carbonite ,no4 #b ,do4 99,carbonite ,no4 #c ,do4 99,carbonite ,no4 #a-,l4 ,f4 ,do4 99,carbonite ,no4 #b-,l4 ,f4 ,do4 99,coalite ,no4 #a ,potts ,powder ,co41 ,new ,york ,city4 99,coalite ,no4 #b-;,d4 ,do4 99,coal special ,no4 #a ,keystone ,powder ,co41 ,emporium1 ,pa4 99,coal special ,no4 #b ,do4 99,collier dynamite ,no4 #b4 ,sinnamahoning ,powder ,manufacturing ,co41 ,emporium1 ,pa4 99,collier dynamite ,no4 #d4 ,do4 99,collier dynamite ,no4 #e4 ,do4 ,giant ,a low-flame dynamite4 ,giant ,powder ,co4 7,con471 ,giant1 ,cal4 ,giant ,b low-flame dynamite4 ,do4 ,giant ,c low-flame dynamite4 ,do4 99,masurite ,m4 ,l4 ,f4 ,masurite ,explosives ,co41 ,sharon1 ,pa4 99,meteor dynamite4 ,e4 ,i4 ,du ,pont de ,nemours ,powder ,co41 ,wilmington1 ,del4 ,mine-ite ,a4 ,burton ,powder ,co41 ,pittsburg1 ,pa4 ,mine-ite ,b4 ,do4 99,monobel4 ,e4 ,i4 ,du ,pont de ,nemours ,powder ,co41 ,wilmington1 ,del4 ,tunnelite ,no4 #e4 ,g4 ,r4 ,mc,abee ,powder and ,oil ,co41 ,pittsburg1 ,pa4 ,tunnelite ,no4 #f4 ,do4 ,tunnelite ,no4 #g4 ,do4 ,tunnelite ,no4 #h4 ,do4 ---------------------------------------- --------------------------- 8,provided3 8#a4 ,that the explosive is in all respects similar to sample submitted by the manufacturer for test4 8#b4 ,that ,no4 #f detonators1 preferably ,no4 #f electric detonators 7double strength71 are used of not less strength than #a gram charge1 consisting by weight of #ij parts of mercury fulminate and #aj parts of potassium chlorate 7or its equivalent71 except for the explosive ',masurite ,m4 ,l4 ,f41' for which the detonator shall be of not less strength than #a grams charge4 8#c4 ,that the explosive1 if frozen1 shall be thoroughly thawed in a safe and suitable manner before use4 8#d4 ,that the amount used in practice does not exceed #a pounds 7#fhj grams71 properly tamped4 8,the above partial list includes all the permissible explosives that have passed these tests prior to ,october #a1 #aiji4 ,the announcement of the passing of like tests by other explosives will be made public immediately after the completion of the tests4 8,with a view to the wise use of these explosives it may be well in this connection to point out again certain differences between the permissible explosives as a class and the black powders now so generally used in coal mining1 as follows3 87a7 ,with equal quantities of each1 the flame of the black powder is more than three times as long and has a duration three thousand to more than four thousand times that of one of the permissible explosives2 the rate of explosion also is slower4 87b7 ,the permissible explosives are one and one-fourth to one and three-fourths times as strong and are said1 if properly used1 to do twice the work of black powder in bringing down coal2 hence only half the quantity need be used4 87c7 ,with #a pound of a permissible explosive or #b pounds of black powder1 the quantity of noxious gases given off from a shot averages approximately the same1 the quantity from the black powder being less than from some of the permissible explosives and slightly greater than from others4 ,the time elapsing after firing before the miner returns to the working face or fires another shot should not be less for permissible explosives than for black powder4 8,the use of permissible explosives should be considered as supplemental to and not as a substitute for other safety precautions in mines where gas or inflammable coal dust is present under conditions indicating danger4 ,as stated above1 they should be used with strong detonators1 and the charge used in practice should not exceed #a pounds and in many cases need not exceed #a pound4 8,,joseph ,a4 ,,holmes1 8,expert in ,charge ,technologic ,branch4 8,approved1 ,october #aa1 #aiji4 8,h4 ,c4 ,,rizer1 8,acting ,director40 ,the second list contains #ca explosives which the ,government is prepared to brand as permissible1 and therefore comparatively safe1 for use in gaseous and dusty mines4 ,an equally large number of so-called safety powders failed to pass these tests4 ,immediately on the passing of the tests1 as to the permissibility of any explosive1 the facts are reported to the manufacturer and to the various ,state mine inspectors4 ,when published1 the permissible lists were issued to all explosives manufacturers1 all mine operators in the ,united ,states1 and ,state inspectors4 ,the effect has been the enactment1 by three of the largest coal-producing ,states1 of legislation or regulations prohibiting the use of any but permissible explosives in gaseous or dusty mines1 and other ,states must soon follow4 ,to prevent fraud1 endeavor is being made to restrict the use of the brand 8,permissible ,explosive1 ,u4,s4 ,testing ,station1 ,pittsburg1 ,pa410 to only such boxes or packages as contain listed permissible explosives4 ,as these tests clearly demonstrate1 both in the records thereof and visually to such as follow them1 that certain explosives1 especially those which are slow-burning like black powder1 or produce high temperature in connection with comparative slow burning1 will ignite mixtures of gas and air1 or mixtures of coal dust and air1 and cause explosions4 ,the results point out clearly to all concerned1 the danger of using such explosives4 ,the remedy is also made available by the announcement of the names of a large number of explosives now on the market at reasonable cost1 which will not cause explosions under these conditions4 ,it is believed that when permissible explosives are generally adopted in coal mines1 this source of danger will have been greatly minimized4 ,explosives ,investigations4--,questions have arisen on the part of miners or of mine operators as to the greater cost in using permissible explosives due to their expense1 which is slightly in excess of that of other explosives2 as to their greater shattering effect in breaking down the coal1 and in giving a smaller percentage of lump and a larger percentage of slack2 and as to the possible danger of breathing the gases produced4 ,observations made in mines by ,mr4 ,j4 ,j4 ,rutledge1 an experienced coal miner and careful mining engineer connected with the ,geological ,survey1 as to the amount of coal obtained by the use of permissible and other explosives1 tend to indicate that the permissible explosives are not more1 but perhaps less expensive than others1 in view of the fact that1 because of their greater relative power1 a smaller quantity is required to do the work than is the case1 say1 with black powder4 ,on the other hand1 for safety and for certainty of detonation1 stronger detonators are recommended for use with permissible explosives1 preferably electric detonators4 ,these may cost a few cents more per blast than the squib or fuse1 but there is no danger that they will ignite the gas1 and the difference in cost is1 in some measure1 offset by the greater certainty of action and the fact that they produce a much more powerful explosion1 thus again permitting the use of still smaller quantities of the explosive and1 consequently1 reducing the cost4 ,these investigations are still in progress4 ,concerning the shattering of the coal3 ,this is being remedied in some of the permissible explosives by the introduction of dopes1 moisture1 or other means of slowing down the disruptive effect1 so as to produce the heaving and breaking effect obtained with the slower-burning powders instead of the shattering effect produced by dynamite4 ,there is every reason to believe that as the permissible explosives are perfected1 and as experience develops the proper methods of using them1 this difficulty will be overcome in large measure4 ,this matter is also being investigated by the ,survey mining engineers and others1 by the actual use of such explosives in coal-mining operations4 ,of the gases given off by explosives1 those resulting from black powder are accompanied by considerable odor and smoke1 and1 consequently1 the miners go back more slowly after the shots1 allowing time for the gases to be dissipated by the ventilation4 ,with the permissible explosive1 the miner1 seeing no smoke and observing little odor1 is apt to be incautious1 and to think that he may run back immediately4 ,as more is learned of the use of these explosives1 this source of danger1 which is1 however1 inconsiderable1 will be diminished4 ,table #a gives the percentages of the gaseous products of combustions from equal weights of black powder and two of the permissible explosives4 ,of the latter1 one represents the maximum amount of injurious gases1 and the other the minimum amount1 between which limits the permissible explosives approximately vary4 ,such noxious gases as may be produced by the discharge of the explosive are diluted by a much larger volume of air1 and are practically harmless1 as proven by actual analysis of samples taken at the face immediately after a discharge4 ,,table #a4 ---------------------------------------- --- ,permissible ,explosives4 ,black ------------------------- powder4 ,maximum4 ,minimum4 ---------------------------------------- -- ,,co#b #bb4h #ad4ej #ba4d ,,co #aj4c #bg4gd #a4c ,n #aj4c #de4ji #gd4d ---------------------------------------- -- ,in addition to investigations as to explosives for use in coal mining1 the ,explosives ,section of the ,geological ,survey analyzes and tests all such materials1 fuses1 caps1 etc41 purchased by the ,isthmian ,canal ,commission1 as well as many other kinds used by the ,government4 ,it is thus acquiring a large fund of useful information1 which will be published from time to time1 relative to the kinds of explosives and the manner of using them best suited to any blasting operations1 either above or under water1 in hard rock1 earth1 or coal4 ,there has been issued from the press1 recently1 a primer of explosives1#g by ,mr4 ,clarence ,hall1 the engineer in charge of these tests1 and ,professor ,c4 ,e4 ,munroe1 ,consulting ,explosives ,chemist1 which contains a large amount of valuable fundamental information1 so simply expressed as to be easily understandable by coal miners1 and yet sufficiently detailed to be a valuable guide to all persons who have to handle or use explosives4 ,in the first chapters are described the various combustible substances1 and the chemical reactions leading to their explosibility4 ,the low and high explosives are differentiated1 and the sensitiveness of fulminate of mercury and other detonators is clearly pointed out4 ,the various explosives1 such as gunpowder1 black blasting powder1 potassium chlorate powders1 nitro-glycerine powders1 etc41 are described1 and their peculiarities and suitability for different purposes are set forth4 ,the character and method of using the different explosives1 both in opening up work and in enclosed work in coal mines1 follow1 with information as to the proper method of handling1 transporting1 storing1 and thawing the same4 ,then follow chapters on squibs1 fuses1 and detonators2 on methods of shooting coal off the solid2 location of bore-holes2 undercutting2 and the relative advantages of small and large charges1 with descriptions of proper methods of loading and firing the same4 ,the subjects of explosives for blasting in rock1 firing machines1 blasting machines1 and tests thereof1 conclude the report4 ,the work of the chemical laboratory in which explosives are analyzed1 and in which mine gases and the gases produced by combustion of explosives and explosions of coal-gas or coal dust are studied1 has been of the most fundamental and important character4 ,the ,government is procuring a confidential record of the chemical composition and mode of manufacture of all explosives1 fuses1 etc41 which are on the market4 ,this information cannot but add greatly to the knowledge as to the chemistry of explosives for use in mines1 and will furnish the basis on which remedial measures may be devised4 ,a bulletin 7shortly to go to press7 which gives the details of the physical tests of the permissible explosives thus far tested1 will set forth elaborately the character of the testing apparatus1 and the method of use and of computing results4#h ,this bulletin contains a chapter1 by ,mr4 ,rutledge1 setting forth in detail the results of his observations as to the best methods of using permissible explosives in getting coal from various mines in which they are used4 ,this information will be most valuable in guiding mining engineers who desire to adopt the use of permissible explosives1 as to the best methods of handling them4 ,electricity in ,mines4--,in connection with the use of electricity in mines1 an informal series of tests has been made on all enclosed electric fuses1 as to whether or not they will ignite an explosive mixture of air and gas when blown out4 ,the results of this work1 which is under the direction of ,mr4 ,h4 ,h4 ,clark1 ,electrical ,engineer for ,mines1 have been furnished the manufacturers for their guidance in perfecting safer fuses1 a series of tests of which has been announced4 ,a series of tests as to the ability of the insulation of electric wiring to withstand the attacks of acid mine waters is in progress1 which will lead1 it is hoped1 to the development of more permanent and cheaper insulation for use in mine wiring4 ,a series of competitive tests of enclosed motors for use in mines has been announced1 and is in progress1 the object being to determine whether or not sparking from such motors will cause an explosion in the presence of inflammable gas4 ,in the grounds outside of ,building ,no4 #aj is a large steel gallery1 much shorter than ,gallery ,no4 #a1 in fact1 but #cj ft4 in length1 and much greater in diameter1 namely1 #aj ft4 7,fig4 #c1 ,plate ,x71 in which electric motors1 electric cutting machines1 and similar apparatus1 are being tested in the presence of explosive mixtures of gas and dust and with large amperage and high voltage1 such as may be used in the largest electrical equipment in mines4 ,the investigation as to the ability of insulation to withstand the effects of acid mine waters has been very difficult and complicated4 ,at first it was believed possible that mine waters from nearby ,pennsylvania mines and of known percentages of acidity could be procured and kept in an immersion tank at approximately any given percentage of strength4 ,this was found to be impracticable1 as these waters seem to undergo rapid change the moment they are exposed to the air or are transported1 in addition to the changes wrought by evaporation in the tank4 ,it has been necessary1 therefore1 to analyze and study carefully these waters with a view to reproducing them artificially for the purpose of these tests4 ,concerning the insulation1 delicate questions have arisen as to a standard of durability which shall be commensurate with reasonable cost4 ,these preliminary points are being solved in conference with the manufacturers1 and it is expected that the results will soon permit of starting the actual tests4 ,safety-,lamp ,investigations4--,many so-called safety lamps are on the market1 and preliminary tests of them have been made in the lamp gallery1 in ,building ,no4 #ag 7,fig4 #b1 ,plate ,x74 ,after nearly a year of endeavor to calibrate this gallery1 and to co-ordinate its results with those produced in similar galleries in ,europe1 this preliminary inquiry has been completed1 and the manufacturers and agents of all safety lamps have been invited to be present at tests of their products at the ,pittsburg laboratory4 ,a circular dated ,november #aith1 #aiji1 contains an outline of these tests1 which are to be conducted under the direction of ,mr4 ,j4 ,w4 ,paul1 an experienced coal-mining engineer and ex-,chief of the ,department of ,state ,mine ,inspection of ,west ,virginia4 ,the lamps will be subjected to the following tests3 7a74--,each lamp will be placed in a mixture of air and explosive natural gas containing #f1 #h1 and #aj of gas1 moving at a velocity of from #bjj to #b1ejj ft4 per min41 to determine the velocity of the air current which will ignite the mixture surrounding the lamp4 ,the current will be made to move against the lamp in a horizontal1 vertical ascending1 and vertical descending direction1 and at an angle of #de1 ascending and descending4 7b74--,after completing the tests herein described1 the lamps will be subjected to the tests described under 7a71 with the air and gas mixture under pressure up to #f in4 of water column4 7c74--,under the conditions outlined in 7a71 coal dust will be introduced into the current of air and gas to determine its effect1 if any1 in inducing the ignition of the gas mixture4 7d74--,each lamp will be placed in a mixture of air and varying percentages of explosive natural gas to determine the action of the gas on the flame of the lamp4 7e74--,each lamp will be placed in a mixture of air and varying percentages of carbonic acid gas to determine the action of the gas on the flame4 7f74--,lamps equipped with internal igniters will be placed in explosive mixtures of air and gas in a quiet state and in a moving current1 and the effect of the igniter on the surrounding mixture will be observed4 7g74--,the oils 7illuminants7 used in the lamps will be tested as to viscosity1 gravity1 flashing point1 congealing point1 and composition4 7h74--,safety-lamp globes will be tested by placing each globe in position in the lamp and allowing the flame to impinge against the globe for #c min4 after the lamp has been burning with a full flame for #aj min41 to determine whether the globe will break4 7i74--,each safety-lamp globe will be mounted in a lighted lamp with up-feed1 and placed for #e min4 in an explosive mixture of air and gas moving at the rate of #a1jjj ft4 per min41 to determine whether the heat will break the glass and1 if it is broken1 to note the character of the fracture4 7j74--,safety-lamp globes will be broken by impact1 by allowing each globe to fall and strike1 horizontally1 on a block of seasoned white oak1 the distance of fall being recorded4 7k74--,each safety lamp globe will be mounted in a safety lamp and1 when the lamp is in a horizontal position1 a steel pick weighing #ajj grammes will be permitted to fall a sufficient distance to break the globe by striking its center1 the distance of the fall to be recorded4 7l74--,to determine the candle power of safety lamps1 a photometer equipped with a standardized lamp will be used4 ,the candle-power will be determined along a line at right angles to the axis of the flame2 also along lines at angles to the axis of the flame both above and below the horizontal4 ,the candle-power will be read after the lamp has been burning #bj min4 7m74--,the time a safety lamp will continue to burn with a full charge of illuminant will be determined4 7n74--,wicks in lamps must be of sufficient length to be at all times in contact with the bottom of the vessel in which the illuminant is contained1 and1 before it is used1 the wick shall be dried to remove moisture4 ,mine-,rescue ,methods4--,mr4 ,paul1 who has had perhaps as wide an experience as any mining man in the investigation of and in rescue work at mine disasters1 is also in charge of the mine-rescue apparatus and training for the ,geological ,survey4 ,these operations consist chiefly of a thorough test of the various artificial breathing apparatus1 or so-called oxygen helmets4 ,most of these are of ,european make and find favor in ,great ,britain1 ,belgium1 ,france1 or ,germany1 largely according as they are of domestic design and manufacture4 ,as yet nothing has been produced in the ,united ,states which fulfills all the requirements of a thoroughly efficient and safe breathing apparatus for use in mine disasters4 ,at the ,pittsburg testing station there are a number of all kinds of apparatus4 ,the tests of these are to determine ease of use1 of repair1 durability1 safety under all conditions1 period during which the supply of artificial air or oxygen can be relied on1 and other essential data4 ,in addition to the central testing station1 sub-stations for training miners1 and as headquarters for field investigation as to the causes of mine disasters and for rescue work in the more dangerous coal fields1 have been established2 at ,urbana1 ,ill41 in charge of ,mr4 ,r4 ,y4 ,williams1 ,mining ,engineer2 at ,knoxville1 ,tenn41 in charge of ,mr4 ,j4 ,j4 ,rutledge1 ,mining ,engineer2 at ,mc,alester1 ,okla41 in charge of ,mr4 ,l4 ,m4 ,jones1 ,assistant ,mining ,engineer2 and at ,seattle1 ,wash41 in charge of ,mr4 ,hugh ,wolflin1 ,assistant ,mining ,engineer4 ,others may soon be established in ,colorado and elsewhere1 in charge of skilled mining engineers who have been trained in this work at ,pittsburg1 and who will be assisted by trained miners4 ,it is not to be expected that under any but extraordinary circumstances1 such as those which occurred at ,cherry1 ,ill41 the few ,government engineers1 located at widely scattered points throughout the ,united ,states1 can hope to save the lives of miners after a disaster occurs4 ,as a rule1 all who are alive in the mine on such an occasion1 are killed within a few hours4 ,this is almost invariably the case after a dust explosion1 and is likely to be true after a gas explosion1 although a fire such as that at ,cherry1 ,ill41 offers the greatest opportunity for subsequent successful rescue operations4 ,the most to be hoped for from the ,government engineers is that they shall train miners and be available to assist and advise ,state inspectors and mine owners1 should their services be called for4 ,it should be borne in mind that the ,federal ,government has no police duties in the ,states1 and that1 therefore1 its employees may not direct operations or have other responsible charge in the enforcement of ,state laws4 ,there is little reason to doubt that these ,federal mining engineers1 both because of their preliminary education as mining engineers and their subsequent training in charge of mine operations1 and more recently in mine-accidents investigations and rescue work1 are eminently fitted to furnish advice and assistance on such occasions4 ,the mere fact that1 within a year1 some of these men have been present at1 and assisted in1 rescue work or in opening up after disasters at nearly twenty of such catastrophes1 whereas the average mining engineer or superintendent may be connected with but one in a lifetime1 should make their advice and assistance of supreme value on such occasions4 ,they cannot be held in any way responsible for tardiness1 however1 nor be unduly credited with effective measures taken after a mine disaster1 because of their lack of responsible authority or charge1 except in occasional instances where such may be given them by the mine owners or the ,state officials1 from a reliance on their superior equipment for such work4 ,successful rescue operations may only be looked for when the time1 now believed to be not far distant1 has been reached when the mine operators throughout the various fields will have their own rescue stations1 as is the practice in ,europe1 and have available1 at certain strategic mines1 the necessary artificial breathing apparatus1 and have in their employ skilled miners who have been trained in rescue work at the ,government stations4 ,then1 on the occurrence of a disaster1 the engineer in charge of the ,government station may advise by wire all those who have proper equipment or training to assemble1 and it may be possible to gather1 within an hour or two of a disaster1 a sufficiently large corps of helmet-men to enable them to recover such persons as have not been killed before the fire--which usually is started by the explosion--has gained sufficient headway to prevent entrance into the mine4 ,without such apparatus1 it is essential that the fans be started1 and the mine cleared of gas4 ,the usual effect of this is to give life to any incipient fire4 ,with the apparatus1 the more dense the gas1 the safer the helmet-men are from a secondary explosion or from the rapid ignition of a fire1 because of the absence of the oxygen necessary to combustion4 ,the miners who were saved at ,cherry1 ,ill41 on ,november #bjth1 #aiji1 owe their lives primarily to the work of the ,government engineers4 ,the sub-station of the ,survey at ,urbana1 ,ill41 was promptly notified of the disaster on the afternoon of ,november #acth4 ,arrangements were immediately made1 whereby ,mr4 ,r4 ,y4 ,williams1 ,mining ,engineer in ,charge1 and his ,assistant1 ,mr4 ,j4 ,m4 ,webb1 with their apparatus1 were rushed by special train to the scene1 arriving early the following day 7,sunday74 ,chief ,mining ,engineer1 ,george ,s4 ,rice1 ,chief of ,rescue ,division1 ,j4 ,w4 ,paul1 and ,assistant ,engineer1 ,f4 ,f4 ,morris1 learned of the disaster through the daily press1 at their homes in ,pittsburg1 on ,sunday4 ,they left immediately with four sets of rescue apparatus1 reaching ,cherry on ,monday morning4 ,meantime1 ,messrs4 ,williams and ,webb1 equipped with oxygen helmets1 had made two trips into the shaft1 but were driven out by the heat4 ,both shafts were shortly resealed with a view to combating the fire1 which had now made considerable headway4 ,the direction of the operations at ,cherry1 was1 by right of jurisdiction1 in charge of the ,state ,mine ,inspectors of ,illinois1 at whose solicitation the ,government engineers were brought into conference as to the proper means to follow in an effort to get into the mine4 ,the disaster was not due to an explosion of coal or gas1 but was the result of a fire ignited in hay1 in the stable within the mine4 ,the flame had come through the top of the air-shaft1 and had disabled the ventilating fans4 ,a rescue corps of twelve men1 unprotected by artificial breathing apparatus1 had entered the mine1 and all had been killed4 ,when the shafts were resealed on ,monday evening1 the #aeth1 a small hole was left for the insertion of a water-pipe or hose4 ,during the afternoon and evening1 a sprinkler was rigged up1 and1 by ,tuesday morning1 was in successful operation1 the temperature in the shaft at that time being #aji ,fahr4 ,after the temperature had been reduced to about #ajj1 the ,federal engineers volunteered to descend into the shaft and make an exploration4 ,the rescue party1 consisting of ,messrs4 ,rice1 ,paul1 and ,williams1 equipped with artificial breathing apparatus1 made an exploration near the bottom of the air-shaft and located the first body4 ,after they had returned to the surface1 three of the ,illinois ,state ,inspectors1 who had previously received training by the ,government engineers in the use of the rescue apparatus1 including ,inspectors ,moses and ,taylor1 descended1 made tests of the air1 and found that with the fan running slowly1 it was possible to work in the shaft4 ,the rescue corps then took hose down the main shaft1 having first attached it to a fire engine belonging to the ,chicago ,fire ,department4 ,water was directed on the fire at the bottom of the shaft1 greatly diminishing its force1 and it was soon subdued sufficiently to permit the firemen to enter the mine without the protection of breathing apparatus4 ,unfortunately1 these operations could be pursued only under the most disadvantageous circumstances and surrounded by the greatest possible precautions1 due to the frequent heavy falls of roof--a result of the heating by the mine fire--and the presence of large quantities of black-damp4 ,all movements of unprotected rescuers had to be preceded by exploration by the trained rescue corps1 who analyzed the gases1 as the fire still continued to burn1 and watched closely for falls1 possible explosions1 or a revival of the fire4 ,while the heavy work of shoring up1 and removing bodies1 was being carried on by the unprotected rescue force1 the helmet-men explored the more distant parts of the mine1 and on ,saturday afternoon1 ,november #bjth1 one week after the disaster1 a room was discovered in which a number of miners1 with great presence of mind1 had walled themselves in in order to keep out the smoke and heat4 ,from this room #bj living men were taken1 of whom #ab were recovered in a helpless condition1 by the helmet-men4 ,this is not the first time this ,government mining corps has performed valiant services4 ,directly and indirectly the members have saved from fifteen to twenty lives in the short time they have been organized4 ,at the ,marianna1 ,pa41 disaster1 the corps found one man still alive among #aej bodies1 and he was brought to the surface4 ,he recovered entirely after a month in the hospital4 ,at the ,leiter mine1 at ,zeigler1 ,ill41 two employees1 who had been trained in the use of the oxygen helmets by members of the ,government's corps1 went down into the mine1 following an explosion1 and brought one man to the surface1 where they resuscitated him4 ,equally good service1 either in actual rescue operations1 or in explorations after mine disasters1 or in fire-fighting1 has been rendered by this force at the ,darr1 ,star ,junction1 ,hazel1 ,clarinda1 ,sewickley1 ,berwind-,white ,no4 #cg1 and ,wehrum1 ,pa41 mine disasters2 at ,monongah and ,lick ,branch1 ,w4 ,va42 at ,deering1 ,sunnyside1 and ,shelburn1 ,ind41 ,jobs1 ,ohio1 and at ,roslyn1 ,wash4 ,explosives ,laboratory4--,the rooms grouped at the south end of ,building ,no4 #ba1 at ,pittsburg1 are occupied as a laboratory for the chemical examination and analysis of explosives1 and are in charge of ,mr4 ,w4 ,o4 ,snelling4 ,samples of all explosives used in the testing gallery1 ballistic pendulum1 pressure gauge1 and other testing apparatus1 are here subjected to chemical analysis in order to determine the component materials and their exact percentages4 ,tests are also made to determine the stability of the explosive1 or its liability to decompose at various temperatures1 and other properties which are of importance in showing the factors which will control the safety of the explosive during transportation and storage4 ,in the investigation of all explosives1 the first procedure is a qualitative examination to determine what constituents are present4 ,owing to the large number of organic and inorganic compounds which enter into the composition of explosive mixtures1 this examination must be thorough4 ,several hundred chemical bodies have been used in explosives at different times1 and some of these materials can be separated from others with which they are mixed only by the most careful and exact methods of chemical analysis4 ,following the qualitative examination1 a method is selected for the separation and weighing of each of the constituents previously found to be present4 ,these methods1 of course1 vary widely1 according to the particular materials to be separated1 it being usually necessary to devise a special method of analysis for each explosive1 unless it is found1 by the qualitative analysis1 to be similar to some ordinary explosive1 in which case the ordinary method of analysis of that explosive can be carried out4 ,most safety powders require special treatment1 while most grades of dynamite and all ordinary forms of black blasting powder are readily analyzed by the usual methods4 ,the examination of black blasting powder has been greatly facilitated and1 at the same time1 made considerably more accurate1 by means of a densimeter devised at this laboratory4 ,in this apparatus a ,torricellian vacuum is used as a means of displacing the air surrounding the grains of powder1 and through very simple manipulation the true density of black powder is determined with a high degree of accuracy4 ,in ,building ,no4 #ag there is an apparatus for separating or grading the sizes of black powder 7,fig4 #a1 ,plate ,x74 ,by means of two factors1 the moisture coefficient and the hygroscopic coefficient1 which have been worked out at this laboratory1 a number of important observations can be made on black powder1 in determining the relative efficiency of the graphite coating to resist moisture1 and also as a means of judging the thoroughness with which the components of the powder are mixed4 ,the moisture coefficient relates to the amount of moisture which is taken up by the grains of the powder in a definite time under standard conditions of saturation2 and the hygroscopic coefficient relates to the affinity of the constituents of the powder for moisture under the same standard conditions4 ,besides the examination of explosives used at the testing station1 those for the ,reclamation ,service1 the ,isthmian ,canal ,commission1 and other divisions of the ,government1 are also inspected and analyzed at the explosives laboratory4 ,at the present time1 the ,isthmian ,canal ,commission is probably the largest user of explosives in the world1 and samples used in its work are inspected1 tested1 and analyzed at this laboratory1 and at the branch laboratories at ,gibbstown and ,pompton ,lakes1 ,n4,j41 and at ,xenia1 ,ohio4 ,aside from the usual analysis of explosives for the ,isthmian ,canal ,commission1 special tests are made to determine the liability of the explosive to exude nitro-glycerine1 and to deteriorate in unfavorable weather conditions4 ,these tests are necessary1 because of the warm and moist climate of the ,isthmus of ,panama4 ,gas and ,dust ,gallery ,no4 #a4--;,gallery ,no4 #a is cylindrical in form1 #ajj ft4 long1 and has a minimum internal diameter of #f ft4 ,it consists of fifteen similar sections1 each #f ft4 long and built up in in-and-out courses4 ,the first three sections1 those nearest the concrete head1 are of -in4 boiler-plate steel1 the remaining twelve sections are of -in4 boiler-plate steel1 and have a tensile strength of1 at least1 #ee1jjj lb4 per sq4 in4 ,each section has one release pressure door1 centrally placed on top1 equipped with a rubber bumper to prevent its destruction when opened quickly4 ,in use1 this door may be either closed and unfastened1 closed and fastened by stud-bolts1 or left open4 ,each section is also equipped with one -in4 plate-glass window1 #f by #f in41 centrally placed in the side of the gallery 7,fig4 #a1 and ,figs4 #a and #b1 ,plate ,,vi74 ,the sections are held together by a lap-joint4 ,at each lap-joint there is1 on the interior of the gallery1 a #b-;in4 circular1 angle iron1 on the face of which a paper diaphragm may be placed and held in position by semicircular washers1 studs1 and wedges4 ,these paper diaphragms are used to assist in confining a gas-and-air mixture4 ,illustration3 ,fig4 #a4 ,,explosives ,,testing ,,gallery ,no4 #a ,natural gas from the mains of the ,city of ,pittsburg is used to represent that found in the mines by actual analysis4 ,a typical analysis of this gas is as follows3 ,volumetric ,analysis of ,typical ,natural ,gas4 ,hydrogen gases #j ,carbon dioxide #j4a ,oxygen #j ,heavy hydrocarbons #j ,carbon monoxide #j ,methane #ha4h ,ethane #af4h ,nitrogen #a4c ,the volume of gas used is measured by an accurate test meter reading to one-twentieth of a cubic foot4 ,the required amount is admitted near the bottom1 to one or more of the #bj-;ft4 divisions of the gallery1 from a #b-;in4 pipe1 #ad ft4 long4 ,the pipe has perforations arranged so that an equal flow of gas is maintained from each unit length4 ,each #bj-;ft4 division of the gallery is further equipped with an exterior circulating system1 as shown by ,fig4 #a1 thus providing an efficient method of mixing the gas with the air4 ,for the first division this circulating system is stationary1 a portion of the piping being equipped with heating coils for maintaining a constant temperature4 ,the other divisions have a common circulating system mounted on a truck which may be used on any of these divisions4 ,valves are provided for isolating the fan so that a possible explosion will not injure it4 ,in the center section of each division is an indicator cock which is used to provide means of recording pressures above and below atmospheric1 or of sampling the air-and-gas mixture4 ,the first division of the gallery is equipped with shelves laterally placed1 for the support of coal dust4 ,the cannon in which the explosive is fired is placed in the concrete head1 the axial line of the bore-hole being coincident with that of the gallery4 ,this cannon 7,fig4 #b7 is similar to that used in the ballistic pendulum4 ,the charge is fired electrically from the observation room4 ,to minimize the risk of loading the cannon1 the charger carries in his pocket the plug of a stage switch 7the only plug of its kind on the ground71 so that it is impossible to complete the circuit until the charger has left the gallery4 ,that portion of the first division of the gallery which is not embedded in concrete1 has a #c-;in4 covering made up of blocks of magnesia1 asbestos fiber1 asbestos1 cement1 a thin layer of #h-oz4 duck1 and strips of water-proof roofing paper1 the whole being covered with a thick coat of graphite paint4 ,the object of this covering is to assist in maintaining a constant temperature4 ,illustration3 ,,plate ,,vii4 ,fig4 #a4--;,bichel ,pressure ,gauges4 ,fig4 #b4--,rate of ,detonation ,recorder4 ,the entire gallery rests on a concrete foundation #aj ft4 wide1 which has a maximum height of #d ft4 and a minimum height of #b ft4 ,the concrete head in which the cannon is placed completely closes that end of the gallery4 ,a narrow drain extends under the entire length of the gallery1 and a tapped hole at the bottom of each section provides an efficient means of drainage4 ,illustration3 ,fig4 #b4 cannon as described in text ,the buildings near the gallery are protected by two barricades near the open end1 each #aj ft4 high and #cj ft4 long4 ,a back-stop1 consisting of a swinging steel plate1 #f ft4 high and #i ft4 long1 #ej ft4 from the end of the gallery1 prevents any of the stemming from doing damage4 ,tests are witnessed from an observation room1 a protected position about #fj ft4 from the gallery4 ,the walls of the room are #ah in4 thick1 and the line of vision passes through a -in4 plate glass1 #f in4 wide and #cg ft4 long1 and is further confined by two external guards1 each #cg ft4 long and #c ft4 wide4 ,in this gallery a series of experiments has been undertaken to determine the amount of moisture necessary with different coal dusts1 in order to reduce the likelihood of a coal-dust explosion from a blown-out shot of one of the dangerous types of explosives4 ,coal dust taken from the roads of one of the coal mines in the ,pittsburg district required at least #ab of water to prevent an ignition4 ,it has also been proven that the finer the dust the more water is required1 and when it was #ajj-mesh fine1 #cj of water was required to prevent its ignition by the flame of a blown-out shot in direct contact4 ,the methods now used in sprinkling have been proven entirely insufficient for thoroughly moistening the dust1 and hence are unreliable in preventing a general dust explosion4 ,at this station successful experiments have been carried out by using humidifiers to moisten the atmosphere after the temperature of the air outside the gallery has been raised to mine temperature and drawn through the humidifiers4 ,it has been found that if a relative humidity of #ij1 at a temperature of #fj ,fahr41 is maintained for #dh hours1 simulating summer conditions in a mine1 the absorption of moisture by the dust and the blanketing effect of the humid air prevent the general ignition of the dust4 ,these humidity tests have been run in ,gas and ,dust ,gallery ,no4 #a with special equipment consisting of a ,koerting exhauster having a capacity of #bdj1jjj cu4 ft4 per hour1 which draws the air out of the gallery through the first doorway1 or that next the concrete head in which the cannon is embedded4 ,the other end of the gallery is closed by means of brattice cloth and paper diaphragms1 the entire gallery being made practically air-tight4 ,the air enters the fifteenth doorway through a box1 passing over steam radiators to increase its temperature1 and then through the humidifier heads4 ,,explosives ,,testing ,,apparatus4 ,there is no exposed woodwork in ,building ,no4 #ag1 which is #dj by #fj ft41 two stories high1 and substantially constructed of heavy stone masonry1 with a slate roof4 ,the structure within is entirely fire-proof4 ,iron columns and girders1 and wooden girders heavily encased in cement1 support the floors which are either of cement slab construction or of wooden flooring protected by expanded metal and cement mortar1 both above and beneath4 ,at one end1 on the ground floor1 is the exposing and recording apparatus for flame tests of explosives1 also pressure gauges1 and a calorimeter1 and1 at the other end1 is a gallery for testing safety lamps4 ,the larger portion of the second floor is occupied by a gas-tight training room for rescue work1 and an audience chamber1 from which persons interested in such work may observe the methods of procedure4 ,a storage room for rescue apparatus and different models of safety lamps is also on this floor4 ,the disruptive force of explosives is determined in three ways1 namely1 by the ballistic pendulum1 by the ,bichel pressure gauge1 and by ,trauzl lead blocks4 ,ballistic ,pendulum4--,the disruptive force of explosives1 as tested by the ballistic pendulum1 is measured by the amount of oscillation4 ,the standard unit of comparison is a charge of lb4 of #dj nitro-glycerine dynamite4 ,the apparatus consists essentially of a #ab-;in4 mortar 7,fig4 #c1 ,plate ,,vi71 weighing #ca1fjj lb41 and suspended as a pendulum from a beam having knife-edges4 ,a steel cannon is mounted on a truck set on a track laid in line with the direction of the swing of the mortar4 ,at the time of firing the cannon may be placed #a_/af-;in4 from the muzzle of the mortar4 ,the beam1 from which the mortar is suspended1 rests on concrete walls1 #ea by #abj in4 at the base and #aci in4 high4 ,on top of each wall is a #a-;in4 base-plate1 #g by #dh in41 anchored to the wall by -in4 bolts1 #bh in4 long4 ,the knife-edges rest on bearing-plates placed on these base-plates4 ,the bearing-plates are provided with small grooves for the purpose of keeping the knife-edges in oil and protected from the weather4 ,the knife-edges are each #f in4 long1 #b-aa_/af in4 deep from point to back1 #b in4 wide at the back1 and taper #ej with the horizontal1 starting on a line #a in4 from the back4 ,the point is rounded to conform to a radius of in4 ,the back of each is #b in4 longer than the edge1 making a total length of #aj in41 and is #a in4 deep and #ab in4 wide4 ,this shoulder gives bolting surface to the beam from which the mortar is hung4 ,the beam is of solid steel1 has a #d by #h-;in4 section1 and is #hg in4 long4 ,heavy steel castings are bolted to it to take the threads of the machine-steel rods which form the saddles on which the mortar is suspended4 ,the radius of the swing1 measured from the point of the knife-edges to the center of the trunnions1 is #hi in4 ,the cannon consists of two parts1 a jacket and a liner4 ,the jacket is #cf in4 long1 has an external diameter of #bd in41 and internal diameters of #i and #g in4 ,it is made of the best cast steel or of forged steel4 ,the liner is #cf in4 long1 with a #a-;in4 shoulder1 #g in4 from the back1 changing the diameter from #i to #g in4 ,the bore is smooth1 being #b in4 in diameter and #ba in4 long4 ,the cannon rests on a #d-wheel truck1 to which it is well braced by straps and rods4 ,a track of #cj-;in4 gauge extends about #i ft4 from the muzzle of the mortar to the bumper for the cannon4 ,the shot is fired by an electric firing battery1 from the first floor of ,building ,no4 #ag1 about #aj yd4 away4 ,to insure the safety of the operator and the charger1 the man who loads the cannon carries a safety plug without which the charge cannot be exploded4 ,the wires for connecting to the fuse after charging are placed conveniently1 and the safety plug is then inserted in a box at the end of the west wall4 ,the completion of the firing battery by the switch at the firing place is indicated by the flashing of a red light1 after which all that is necessary to set off the charge is to press a button on the battery4 ,an automatic recording device at the back of the mortar records the length of swing which1 by a vernier1 may be read to #a_/bjj in4 ,bichel ,pressure ,gauges4--,pressure gauges are constructed for the purpose of determining the unit disruptive force of explosives detonating at different rates of velocity1 by measuring pressures developed in an enclosed space from which the generated gases cannot escape4 ,the apparatus consists of a stout steel cylinder1 which may be made absolutely air-tight2 an air-pump and proper connections for exhausting the air in the cylinder to a pressure equivalent to #aj mm4 of mercury2 an insulated plug for providing the means of igniting the charge2 a valve by which the gaseous products of combustion may be removed for subsequent analysis2 and an indicator drum 7,fig4 #a1 ,plate ,,vii7 with proper connections for driving it at a determinable speed4 ,this apparatus is in the southeast corner of ,building ,no4 #ag4 ,the cylinder is #ca in4 long1 #ai in4 in diameter1 and is anchored to a solid concrete footing at a convenient height for handling4 ,the explosion chamber is #ai in4 long and #g;in4 in diameter1 with a capacity of exactly #ae liters4 ,the cover of the cylinder is a heavy piece of steel held in place by stout screw-bolts and a heavy steel clamp4 ,the charge is placed on a small wire tripod1 and connections are made with a fuse to an electric firing battery for igniting the charges4 ,the cover is drawn tight1 with the twelve heavy bolts against lead washers4 ,the air in the cylinder is exhausted to #aj mm41 mercury column1 in order to approach more closely the conditions of a stemmed charge exploding in a bore-hole inaccessible to air2 the indicator drum is placed in position and set in motion2 and1 finally1 the shot is fired4 ,the record shown on the indicator card is a rapidly ascending curve for quick explosives and a shallower1 slowly rising curve for explosives of slow detonation4 ,when the gases cool1 the curve merges into a straight line1 which indicates the pressures of the cooled gases on the sides of the chamber4 ,illustration3 ,,plate ,,viii4 ,fig4 #a4--;,explosives ,calorimeter4 ,fig4 #b4--;,building ,no4 #ag1 and ,flame-,test ,apparatus4 ,fig4 #c4--,small ,lead ,block ,test4 ,since the ratio of the volume of the cylinder to the volume of the charge may be computed1 the pressure of the confined charge may also be found1 and this pressure often exceeds #ajj1jjj lb4 per sq4 in4 ,the cooling effect of the inner surface on the gaseous products of combustion1 a vital point in computations of the disruptive force of explosives by this method1 is determined by comparing the pressures obtained in the original cylinder with those in a second cylinder of larger capacity1 into which has been inserted one or more steel cylinders to increase the superficial area while keeping the volume equal to that of the first cylinders4 ,by comparing results1 a curve may be plotted1 which will determine the actual pressures developed1 with the surface-cooling effect eliminated4 ,trauzl ,lead ,blocks4--,the lead-block test is the method adopted by the ,fifth ,international ,congress of ,applied ,chemistry as the standard for measuring the disruptive force of explosives4 ,the unit by this test is defined to be the force required to enlarge the bore-hole in the block to an amount equivalent to that produced by #aj grammes of standard #dj nitro-glycerine dynamite stemmed with #ej grammes of dry sand under standard conditions as produced with the tamping device4 ,the results of this test1 when compared with those of the ,bichel gauge1 indicate that1 for explosives of high detonation1 the lead block is quite accurate1 but for slow explosives1 such as gunpowder1 the expansion of the gases is not fast enough to make comparative results of value4 ,the reason for this is that the gases escape through the bore of the block rather than take effect in expanding the bore-hole4 ,the lead blocks are cylindrical1 #bjj mm4 in diameter1 and #bjj mm4 high4 ,each has a central cavity1 #be mm4 in diameter and #abe mm4 deep 7,fig4 #a1 ,plate ,,ix71 in which the charge is placed4 ,the blocks are made of desilverized lead of the best quality1 and1 as nearly as possible1 under identical conditions4 ,the charge is placed in the cavity and prepared for detonation with an electrical exploder and stemming4 ,after the explosion the bore-hole is pear-shaped1 the size of the cavity depending1 not only on the disruptive power of the explosive1 but also on its rate of detonation1 as already indicated4 ,the size of the bore-hole is measured by filling the cavity with water from a burette4 ,the difference in the capacity of the cavity before and after detonation indicates the enlarging power of the explosive4 ,calorimeter4--,the explosion calorimeter is designed to measure the amount of heat given off by the detonation of explosive charges of #ajj grammes4 ,the apparatus consists of the calorimeter bomb 7,fig4 #a1 ,plate ,,viii71 the inner receiver or immersion vessel1 a wooden tub1 a registering thermometer1 and a rocking frame4 ,this piece of apparatus stands on the east side of ,building ,no4 #ag4 ,the bottle-shaped bomb is made of -in4 wrought steel1 and has a capacity of #cj liters4 ,on opposite sides near the top are bored apertures1 one for the exhaust valve for obtaining a partial vacuum 7about #bj mm41 mercury column7 after the bomb has been charged1 the other for inserting the plug through which passes the fuse wire for igniting the charge4 ,the bomb is closed with a cap1 by which the chamber may be made absolutely air-tight4 ,it is #cj in4 high with the cap on1 weighs #aeh lb41 and is handled to and from the immersion vessel by a small crane4 ,the inner receiver is made of #a_/af-;in4 sheet copper1 #cj in4 deep1 and with an inner diameter of #ag in4 ,it is nickel-plated1 and strengthened on the outside with bands of copper wire1 and its capacity is about #gj liters4 ,the outer tub is made of #a-;in4 lumber strengthened with four brass hoops on the outside4 ,it is #cc in4 deep1 and its inner diameter is #ba in4 ,the stirring device1 operated vertically by an electric motor1 consists of a small wooden beam connected to a system of three rings having a horizontal bearing surface4 ,when the apparatus is put together1 the inner receiver rests on a small standard on top of the base of the outer tank1 and the rings of the stirring device are run between the bomb and the inner receiver4 ,the bomb itself rests on a small standard placed on the bottom of the inner receiver4 ,the apparatus is provided with a snugly fitting board cover4 ,the bomb is charged from the top1 the explosive being suspended in its center4 ,the air is exhausted to the desired degree of rarification4 ,the caps are then screwed on1 and the apparatus is set together as described4 ,illustration3 ,,plate ,,ix4 ,fig4 #a4--,trauzl ,lead ,blocks4 ,fig4 #b4--,powder ,flames4 ,the apparatus is assembled on scales and weighed before the water is poured in and after the receiver is filled4 ,from the weight of the water thus obtained and the rise of temperature1 the calorific value may be computed4 ,the charge is exploded by electricity1 while the water is being stirred4 ,the rise in the temperature of the water is read by a magnifying glass1 from a thermometer which measures temperature differences of #j4ja degree4 ,from the readings obtained1 the maximum temperature of explosion may be determined1 according to certain formulas for calorimetric experiments4 ,proper corrections are made for the effects1 on the temperature readings1 of the formation of the products of combustion1 and for the heat-absorbing power of the apparatus4 ,impact ,machine4--,in ,building ,no4 #ag1 at the south side1 is an impact machine designed to gauge the sensitiveness of explosives to shock4 ,for this purpose1 a drop-hammer1 constructed to meet the following requirements1 is used3 ,a substantial1 unyielding foundation2 minimum friction in the guide-grooves2 and no escape or scattering of the explosive when struck by the falling weight4 ,this machine is modeled after one used in ,germany1 but is much improved in details of construction4 ,the apparatus1 ,fig4 #a1 ,plate ,,xi1 consists essentially of the following parts3 ,an endless chain working in a vertical path and provided with lugs2 a steel anvil on which the charge of explosive is held by a steel stamp2 a demagnetizing collar moving freely in vertical guides and provided with jaws placed so that the lugs of the chain may engage them2 a steel weight sliding loosely in vertical guides and drawn by the demagnetizing collar to determinable heights when the machine is in operation2 a second demagnetizing collar1 which may be set at known heights1 and provided with a release for the jaws of the first collar2 and a recording device geared to a vertically-driven threaded rod which raises or lowers1 sets the second demagnetizing collar1 and thus determines the height of fall of the weight4 ,by this apparatus the weight may be lifted to different known heights1 and dropped on the steel stamp which transmits the shock to the explosive4 ,the fall necessary to explode the sample is thus determined4 ,the hammers are of varying weight1 the one generally used weighing #b1jjj grammes4 ,as the sensitiveness of an explosive is influenced by temperature changes1 water at #be cent4 is allowed to flow through the anvil in order to keep its temperature uniform4 ,flame ,test4--,an apparatus1 ,fig4 #b1 ,plate ,,viii1 designed to measure the length and duration of flames given off by explosives1 is placed at the northeast corner of ,building ,no4 #ag4 ,it consists essentially of a cannon1 a photographing device1 and a drum geared for high speed1 to which a sensitized film may be attached4 ,about #ac ft4 outside the wall of ,building ,no4 #ag1 set in a concrete footing1 is a cannon pointing vertically into an encasing cylinder or stack1 #bj ft4 high and #dc in4 in diameter4 ,this cannon is a duplicate of the one used for the ballistic pendulum1 details of which have already been given4 ,the stack or cylinder is of -in4 boiler plate1 in twenty-four sections1 and is absolutely tight against light at the base and on the sides4 ,it is connected with a dark room in ,building ,no4 #ag by a light-tight conduit of rectangular section1 #ab in4 wide1 horizontal on the bottom1 and sloping on the top from a height of #h ft4 at the stack to #ba in4 at the inside of the wall of the building4 ,the conduit is carefully insulated from the light at all joints1 and is riveted to the stack4 ,a vertical slit1 #b in4 wide and #h ft4 long1 coincident with the center line of the conduit1 is cut in the stack4 ,a vertical plane drawn through the center line of the bore-hole of the cannon and that of the slit1 if produced1 intersects the center line of a quartz lens1 and coincides with the center of a stenopaic slit and the axis of the revolving drum carrying the film4 ,the photographing apparatus consists of a shutter1 a quartz lens1 and a stenopaic slit1 #gf by #a4g mm41 between the lens and the sensitized film on the rotary drum4 ,the quartz lens is used because it will focus the ultra-violet rays1 which are those attending extreme heat4 ,the drum is #ej cm4 in circumference and #aj cm4 deep4 ,it is driven by a #bbj-volt motor connected to a tachometer which reads both meters per second and revolutions per minute4 ,a maximum peripheral speed of #bj m4 per sec4 may be obtained4 ,when the cannon is charged1 the operator retires to the dark room in which the recording apparatus is located1 starts the drum1 obtains the desired speed1 and fires the shot by means of a battery4 ,when developed1 the film shows a blur of certain dimensions1 produced by the flame from the charge4 ,from the two dimensions--height and lateral displacement--the length and duration of the flame of the explosive are determined4 ,the results of flame tests of a permissible explosive and a test of black blasting powder1 all shot without stemming1 are shown on ,fig4 #b1 ,plate ,,ix4 ,in this test1 the speed of the drum carrying the black powder negative was reduced to one sixty-fourth of that for the permissible explosives1 in order that the photograph might come within the limits of the negative4 ,in other words1 the duration of the black powder flame1 as shown1 should be multiplied by #fd for comparison with that of the permissible explosive1 which is from #c1ejj to #d1jjj times quicker4 ,apparatus for ,measuring ,rate of ,detonation4--,the rate at which detonation travels through a given length of an explosive can be measured by an apparatus installed in and near ,building ,no4 #ag4 ,its most essential feature is a recording device1 with an electrical connection1 by which very small time intervals can be measured with great exactness4 ,the explosive is placed in a sheet-iron tube about #a in4 in diameter and #d ft4 long1 and suspended by cords in a pit1 #aa ft4 deep and #af ft4 in diameter4 ,this pit was once used as the well of a gas tank1 ,fig4 #b1 ,plate ,,viii4 ,in adapting the pit to its new use1 the tank was cut in two2 the top half1 inverted1 was placed in the pit on a bed of saw-dust1 and the space between the tank and the masonry walls of the pit was filled with saw-dust4 ,the cover of the pit consists of heavy timbers framed together and overlaid by a #ab-;in4 layer of concrete reinforced by six ,i-beams4 ,four straps extend over the top and down to eight 8deadmen0 planted about #h ft4 below the surface of the ground4 ,the recording device1 known as the ,mettegang recorder1 ,fig4 #b1 ,plate ,,vii1 comprises two sparking induction coils and a rapidly revolving metallic drum driven by a small motor1 the periphery of the drum having a thin coating of lampblack4 ,a vibration tachometer which will indicate any speed between #ej and #aej rev4 per sec41 is directly connected to the drum1 so that any chance of error by slipping is eliminated4 ,the wires leading to the primary coils of the sparking coils pass through the explosive a meter or more apart4 ,wires lead from the secondary coils to two platinum points placed a fraction of a millimeter from the periphery of the drum4 ,a separate circuit is provided for the firing lines4 ,in making a test1 the separate cartridges1 with the paper trimmed from the ends1 are placed1 end to end1 in the sheet-iron tube2 the drum is given the desired peripheral speed1 and the charge is exploded4 ,the usual length between the points in the tube is #a m41 and the time required for the detonation of a charge of that length is shown by the distance between the beginning of two rows of dots on the drum made by the sparks from the secondary coil circuits1 the dots starting the instant the primary circuits are broken by the detonation4 ,at one end of the drum are gear teeth1 #a mm4 apart on centers1 which can be made to engage a worm revolving a pointer in front of a dial graduated to hundredths2 by means of this and a filar eyepiece1 the distance between the start of the two rows of spark dots on the drum can be measured accurately to #j4ja mm4 ,as the drum is #ejj mm4 in circumference1 and its normal speed is #hf rev4 per sec41 it is theoretically possible to measure time to one four-millionth of a second1 though with a cartridge #a m4 long1 such refinement has not been found necessary4 ,the use of small lead blocks affords another means of determining the rate of detonation or quickness of an explosive4 ,each block 7a cylinder1 #b in4 long and #a in4 in diameter7 is enclosed in a piece of paper so that a shell is formed above the block1 in which to place the charge4 ,a small steel disk of the same diameter as the block is first placed in the shell on top of the block1 then the charge with a detonator is inserted4 ,the charge is customarily #ajj grammes4 ,on detonation of the charge1 a deformation of the lead takes place1 the amount of which is due to the quickness of the explosive used 7,fig4 #c1 ,plate ,,viii74 ,sample ,record of ,tests4 ,the procedure followed in the examination of an explosive is shown by the following outline3 #a4--,physical ,examination4 7a74--,record of appearance and marks on original package4 7b74--,dimensions of cartridge4 7c74--,weight of cartridge1 color and specific gravity of powder4 #b4--;,chemical ,analysis4 7a74--,record of moisture1 nitro-glycerine1 sodium or potassium nitrate1 and other chemical constituents1 as set forth by the analysis2 percentage of ash1 hygroscopic coefficient--the amount of water taken up in #bd hours in a saturated atmosphere1 at #ae cent41 by #e grammes1 as compared with the weight of the explosive4 7b74--,analysis of products of combustion from #ajj grammes1 including gaseous products1 solids1 and water4 7c74--,composition of gaseous products of combustion1 including carbon monoxide and carbon dioxide1 hydrogen1 nitrogen1 etc4 7d74--,composition of solid products of combustion1 subdivided into soluble and insoluble4 #c4--;,a ,typical ,analysis of ,natural ,gas4 ,used in tests1 as follows3 ,carbon dioxide #j4j per cent4 ,heavy hydrocarbons #j4b 0 0 ,oxygen #j4a 0 0 ,carbon monoxide #j4j 0 0 ,methane #hb4d 0 0 ,ethane #ae4c 0 0 ,nitrogen #b4j 0 0 ----- #ajj4jj per cent4 #d4--,typical ,analysis of ,bituminous ,coal ,dust1 #ajj-,mesh ,fine1 ,used in ,tests4 ,moisture #a4ij ,volatile matter #ce4je ,fixed carbon #eh4ib ,ash #d4ac ------ #ajj4jj ,sulphur #a4jd #e4--;,an ,average ,analysis of ,detonators4 ,used on ,trauzl lead blocks1 pressure gauge1 calorimeter1 and small lead blocks3 ,m - l7l_/m74 ,triple-strength exploder4 ,charge #a4egbi grammes4 ,mercury ,chlorate fulminate4 of potash4 ,specification #hi4gc #aj4bg ,used on all other tests3 ,m - #bfj7l_/m74 ,double-strength exploder4 ,charge #j4ihje grammes4 ,mercury ,chlorate fulminate4 of potash4 ,specification #ia4ca #h4fi #f4--;,ballistic-,pendulum ,tests4 ,this record includes powder used1 weight of charge1 swing of mortar1 and unit disruptive charge1 the latter being the charge required to produce a swing of the mortar equal to that produced by lb4 7#bbg grammes7 of #dj dynamite1 or #c4ja in4 #g4--,record of ,tests4 ,tests ,nos4 #a to #e in ,gallery ,no4 #a1 as set forth in preceding circular4 #h4--,trauzl ,lead-,block ,test4 ,powder and test numbers1 expansion of bore-hole in cubic centimeters1 and average expansion compared with that produced by a like quantity 7#aj grammes7 of #dj dynamite1 the latter giving an average expansion of #bid cu4 cm4 #i4--,pressure ,gauge4 ,powder and test number1 weight of charge1 charging density1 height of curve1 pressure developed1 and pressure developed after cooling1 compared with pressure developed after elimination of surface influences by a like quantity 7#ajj grammes7 of #dj dynamite1 the average being #h1dci kg4 per sq4 cm4 #aj4--,rate of ,detonation4 ,powder and test number1 size of cartridge1 and rate of detonation in meters per second1 for comparison with rate of detonation of #dj dynamite1 which1 under the same conditions1 averages #d1fij m4 per sec4 #aa4--;,impact ,machine4 ,explosive and test numbers1 distance of fall 7#b1jjj-;gramme weight7 necessary to cause explosion1 for comparison with length of fall1 #aa cm41 necessary to cause explosion of #dj dynamite4 #ab4--;,distance of ,explosive ,wave ,transmitted by #a4be by #h-;in4 ,cartridge4 ,explosive and test numbers1 weight of cartridge1 distance separating cartridges in tests1 resulting explosion or non-explosion1 for comparison with two cartridges of #dj dynamite1 hung1 under identical conditions1 #ac in4 apart1 end to end1 in which case detonation of the first cartridge will explode the second4 #ac4--;,flame ,test4 ,explosive and test numbers1 charge #ajj grammes with #a lb4 of clay stemming1 average length of flame and average duration of flame1 for comparison with photographs produced by #dj dynamite under like conditions4 ,illustration3 ,,plate ,x4 ,fig4 #a4--,separator for ,grading ,black ,powder4 ,fig4 #b4--,safety ,lamp ,testing ,gallery4 ,fig4 #c4--,mine ,gallery ,no4 #b4 #ad4--,small ,lead ,blocks4 ,powder and test numbers1 weight of charge1 and compression produced in blocks4 #ae4--;,calories ,developed4 ,number of large calories developed per kilogramme of explosive1 for comparison with #a1jjj grammes of #dj dynamite1 which develop1 on an average1 #a1bbi large calories4 ,blasting ,powder ,separator4 ,the grains of black blasting powder are graded by a separator1 similar to those used in powder mills1 but of reduced size4 ,it consists of an inclined wooden box1 with slots on the sides to carry a series of screens1 and a vertical conduit at the end for carrying off the grains as they are screened into separate small bins 7,fig4 #a1 ,plate ,x74 ,at the upper end of the screens is a small #ab by #af-;in4 hopper1 with a sliding brass apron to regulate the feed4 ,the screens are shaken laterally by an eccentric rod operated by hand4 ,the top of the hopper is about #f ft4 above the floor4 ,the box is #f ft4 #aj in4 long1 from tip to tip1 and inclines at an angle of #i degrees4 ,after separation the grains fall through a vertical conduit1 and thence to the bins through zinc chutes1 #a by #b in4 in section4 ,care is taken to have no steel or iron exposed to the powder4 ,the screens are held by light wooden frames which slip into the inclined box from the upper end4 ,in this way1 any or all of the screens may be used at once1 thus separating all grades1 or making only such separations as are desired4 ,the screens with the largest meshes are diagonally-perforated zinc plates4 ,table #b gives the number of holes per square foot in zinc plates perforated with circular holes of the diameters stated4 ,,table #b4--,number of ,holes per ,square ,foot in ,zinc ,plates with ,circular ,perforations4 ------------------------- ,diameter1 ,number in inches of holes4 ------------------------- #a_/b #cec #d_/aj #eah #a_/c #ghb #a_/d #a1cib #a_/f #a1fhj #a_/h #c1def #a_/aj #f1fcf #a_/af #ab1hjj ------------------------- ,the finer meshes are obtained by using linen screens with holes of two sizes1 namely1 #a_/bj in4 square and #a_/bh in4 square4 ,until a few years ago1 black blasting powder was manufactured in the sizes given in ,table #c4 ,,table #c4--;,gradation of ,black ,blasting ,powder4 -------------------- ,grade4 ,mesh4 -------------------- ,,cc #b - #b ,c #b - #c ,f #c - #e ,,ff #e - #h ,,fff #h - #af ,,ffff #af - #bh -------------------- ,in late years there has been considerable demand for special sizes and mixed grains for individual mines1 especially in ,illinois4 ,as no material change has been made in the brands1 the letters now used are not indicative of the size of the grains1 which they are supposed to represent4 ,of #bi samples of black blasting powder recently received from the ,illinois ,powder ,commission1 only #aj were found to contain #ie of the size of grains they were supposed to represent2 #d contained #ij2 #g varied from #hj to #ij2 several others were mixtures of small and large grains1 and were branded ,,ff black blasting powder2 and one sample contained only #h4e of the size of grains it was supposed to represent4 ,the remaining samples showed many variations1 even when sold under the same name4 ,the practice of thus mixing grades is exceedingly dangerous1 because a miner1 after becoming accustomed to one brand of ,,ff powder of uniform separation1 may receive another make of similar brand but of mixed grains1 and1 consequently1 he cannot gauge the quantity of powder to be used4 ,the result is often an over-load or a blown-out shot4 ,the smaller grains will burn first1 and the larger ones may be thrown out before combustion is complete1 and thus ignite any fire-damp present4 ,lamp ,testing ,gallery4 ,at the ,pittsburg testing station1 there is a gallery for testing safety lamps in the presence of various percentages of inflammable gas4 ,in this gallery the safety of the lamps in these gaseous mixtures may be tested1 and it is also possible for mine inspectors and fire bosses to bring their safety lamps to this station1 and test their measurements of percentage of gas1 by noting the length and the appearance of the flame in the presence of mixtures containing known percentages of methane and air4 ,illustration3 ,,plate ,,xi4 ,fig4 #a4--;,impact ,machine4 ,fig4 #b4--,lamp ,testing ,box4 ,the gas-tight gallery used for testing the lamps1 consists of a rectangular conduit 7,fig4 #b1 ,plate ,x71 having sheet-steel sides1 #f mm4 thick and #dcc mm4 wide1 the top and bottom being of channel iron4 ,the gallery rests on two steel trestles1 and to one end is attached a ,no4 #e ,koerting exhauster1 capable of aspirating #ej cu4 m4 per min41 under a pressure of #ejj mm4 of water1 with the necessary valve1 steam separator1 etc4 ,the mouth of the exhauster passes through the wall of the building and discharges into the open air4 ,besides the main horizontal conduit1 there are two secondary conduits connected by a short horizontal length1 and the whole is put together so that the safety lamp under test may be placed in a current of air1 or of air and gas1 which strikes it horizontally1 vertically upward or downward1 or at an angle of #de 7,fig4 #c74 ,the path of the current is determined by detachable sheet-steel doors4 ,illustration3 ,fig4 #c4 ,,safety ,,lamp ,,testing ,,gallery ,there are five double observing windows of plate glass1 which open on hinges4 ,the size of each window is #g by #c in42 the inner glass is in4 thick and the outer one1 in4 thick4 ,these glasses are separated by a space of in4 ,the upper conduit has four safety doors along the top1 each of the inclined conduits has one safety door1 and the walls and windows are provided with rubber gaskets or asbestos packing1 to make them gas-tight4 ,the cross-sectional area of the conduit is #dcd sq4 cm4 ,the air inlet consists of #cf perforations1 #bb mm4 in diameter1 in a bronze plate or diaphragm4 ,the object of this diaphragm is to produce pressure in the conduit before the mixing boxes1 and permit the measuring of the velocity of the current4 ,the air-current1 after passing through the holes1 enters the mixer1 a cast-steel box traversed by #cf copper tubes1 each perforated by #ab openings1 #c mm4 in diameter1 arranged in a spiral along its length and equally spaced4 ,the total cross-sectional area of the tubes is #acg sq4 cm4 ,the explosive gas enters the interior of the box around the tubes through large pipes1 each #ij mm4 in diameter1 passes thence through the #dcb openings in the copper tubes1 and mixes thoroughly with the air flowing through these tubes4 ,the current through the apparatus is induced by the exhauster1 and its course is determined by the position of the doors4 ,the gallery can be controlled so as to provide rapidly and easily a current of known velocity and known percentage of methane4 ,in the explosive current of gas and air1 safety lamps of any size or design can be tested under conditions simulating those found occasionally in mines1 air-currents containing methane in dangerous proportions striking the lamps at different angles1 and the relative safety of the various types of lamps under such conditions can be determined4 ,in this gallery it is also possible to test lighting devices either in a quiet atmosphere or in a moving current1 and1 by subjecting the lamps to air containing known percentages of methane1 it is possible to acquaint the user with the appearance of the flame caps4 ,breathing ,apparatus4 ,with this apparatus1 the wearer may explore a gaseous mine1 approach fires for the purpose of fighting them1 or make investigations after an explosion4 ,its object is to provide air or oxygen to be breathed by the wearer in coal mines1 when the mine air is so full of poisonous gases as to render life in its presence impossible4 ,a variety of forms of rescue helmets and apparatus are on the market1 almost all of ,european manufacture1 which are being subjected to comparative trials as to their durability and safety1 the ease or inconvenience involved in their use1 etc4 ,all consist essentially of helmets which fit air-tight about the head1 or of air-tight nose clamps and mouthpieces 7,fig4 #a1 ,plate ,,xii74 ,these several forms of breathing apparatus are of three types3 #a4--,the liquid-air type1 in which air1 in a liquid state1 evaporates and provides a constant supply of fresh air4 #b4--,the chemical oxygen-producing type1 which artificially makes or supplies oxygen for breathing at about the rate required2 and1 #c4--,the compressed-oxygen type4 ,illustration3 ,,plate ,,xii4 ,fig4 #a4--;,breathing and ,rescue ,apparatus4 ,fig4 #b4--,rescue ,training ,room4 ,apparatus of the first type1 weighing #bj lb41 supplies enough air to last about #c hours1 and the products of breathing pass through a check-valve directly into space4 ,apparatus of the second type supplies oxygen obtained from oxygen-producing chemicals1 and also provides means of absorbing the carbonic acid gas produced in respiration4 ,they contain also the requisite tubes1 valves1 connections1 etc41 for the transmission of the fresh air and the respired air so as to produce sufficient oxygen while in use2 to absorb and purify the products of expiration2 and to convey the fresh air to the mouth without contamination by the atmosphere in which the apparatus is used4 ,three oxygen-generating cartridges are provided1 each supplying oxygen enough for #a hour1 making the total capacity #c hours4 ,changes of cylinders can be made in a few seconds while breathing is suspended4 ,this apparatus weighs from #bj to #be lb41 according to the number of oxygen generators carried4 ,the cartridges for generating oxygen1 provided with this apparatus1 are of no value after having been used for about an hour4 ,the third type of apparatus is equipped with strong cylinders charged with oxygen under high pressure2 two potash regenerative cans for absorbing the carbon dioxide gas exhaled2 a facial helmet2 the necessary valves1 tubes1 etc41 for the control of the oxygen2 and a finimeter which registers the contents of the cylinders in atmospheres and minutes of duration4 ,the two cartridges used for absorbing the carbonic acid gas are of no value after having been in use for two hours4 ,if inhalation is through the mouth alone1 a mouthpiece is attached to the end of the breathing tube by which the air or oxygen is supplied1 the nose is closed by a clip1 and the eyes are protected by goggles4 ,to inhale through both nose and mouth1 the miner wears a helmet or headgear which can be made to fit tightly around the face4 ,the helmet has two tubes attached1 one for inspiration and the other for expiration4 ,in the oxygen-cylinder apparatus these tubes lead to and from rubber sacks used for pure-air and bad-air reserves4 ,mine-,rescue ,training4 ,it has been found in actual service that when a miner1 equipped with breathing apparatus for the first time1 enters a mine in which an explosion has occurred1 he is soon overcome by excitement or nervousness induced by the artificial conditions of breathing imposed by the apparatus1 the darkness and heat1 and the consciousness that he is surrounded with poisonous gases4 ,it has also been found that a brief period of training in the use of such apparatus1 under conditions simulating those encountered in a mine after a disaster1 gives the miner confidence and enables him to use the apparatus successfully under the strain of the vigorous exertion incident to rescue work4 ,the rescue corps consists of five or six miners under the direction of a mining engineer who is experienced in rescue operations and familiar with the conditions existing after mine disasters4 ,the miners work in pairs1 so that one may assist the other in case of accident1 or of injury to the breathing apparatus1 and so that each may watch the condition of the oxygen supply1 as shown by the gauges in the other's outfit4 ,the training is given in the gas-tight room of ,building ,no4 #ag1 or in similar rooms at sub-stations 7,fig4 #b1 ,plate ,,xii74 ,this room is made absolutely dark1 and is filled with formaldehyde gas1 ,,so#b1 ,,co#b1 or ,,co1 produced by burning sulphur or charcoal on braziers4 ,at each period of training1 the miners enter and walk a distance of about #a mile1 the average distance usually traveled from the mine mouth to the working face or point of explosion4 ,they then remove a number of timbers2 lift a quantity of brick or hard lump-coal into wheel-barrows2 climb through artificial tunnels1 up and down inclines1 and over surfaces strewn with coal or stone2 operate a machine with a device attached to it1 which automatically records the foot-pounds of work done2 and perform other vigorous exercise1 during a period of #b hours4 ,this routine is repeated daily during #a week1 after which the rescue corps is considered sufficiently trained for active service4 ,the apparatus used for recording the foot-pounds of work done by the person operating the work machine within the gas-tight rescue room1 comprises a small dial with electrical connections1 which records the number of strokes made by the machine1 and a pencil point which rests on a paper diaphragm1 fastened to a horizontal brass disk4 ,this disk is driven by clockwork1 and makes one complete revolution per hour4 ,when the machine is in operation1 the pencil point works back and forth1 making a broad line on the paper2 when the operator of the machine rests1 the pencil point traces a single line4 ,the apparatus thus records the number of strokes given by the operator during a given time4 ,from the weight lifted1 the height of lift1 and the number of strokes in the given time1 the foot-pounds of work are readily calculated4 ,electric ,testing ,apparatus4 ,on the ground floor of ,building ,no4 #aj1 two rooms are occupied as laboratories for investigating the electrical equipment used in mining operations4 ,the purpose of these investigations is to ascertain the conditions under which electricity of various voltages may be used with safety--in mine haulage1 hoisting1 pumping1 or lighting--in the presence of dangerous mixtures of explosive gases or of dust4 ,it is also proposed to test various kinds of insulation and insulators in this laboratory1 and to determine the durability of such insulation in the presence of such corrosive gases and water as are found in mines4 ,a water-proof wooden tank1 measuring #ae by #e by #e ft41 is installed1 in which insulation and insulating materials are tested under either pure or polluted water4 ,various electric lighting devices and equipment can be connected from a switch-board in ,building ,no4 #ag with ,gas-and-,dust ,gallery ,no4 #b1 for testing the effect of such lighting apparatus in the presence of explosive mixtures of gas and dust1 as set forth on page #bbj4 ,in the electrical laboratory1 ,building ,no4 #aj1 is a booster set developing #fj kw41 and an appropriate switch-board for taking direct current at #bbj volts from the turbo-generator and converting it into current varying from #j to #gej volts4 ,there are also transformers for developing #fj-;cycle1 alternating current at voltages of from #aaj to #b1bjj4 ,the switch-board is designed to handle these various voltages and to communicate them to the apparatus under test in ,building ,no4 #aj1 ,gallery ,no4 #b1 or elsewhere4 ,tests are in progress of insulating materials for use in mines1 and of electric fuses1 lights1 etc41 in ,gallery ,no4 #b 7,fig4 #c1 ,plate ,x71 and in the lamp-testing box 7,fig4 #b1 ,plate ,,xi74 ,it is proposed1 at the earliest possible date1 to make comparative tests of the safety of various mine locomotives and mine-hoisting equipment through the medium of this laboratory1 and it is believed that the results will furnish valuable information as a guide to the safety1 reliability1 and durability of these appliances when electrically operated4 ,electric ,lamp and ,fuse ,testing ,box4--,an apparatus for testing safety lamps and electric lights and fuses1 consists of -in4 iron plates1 bolted together with #a in4 angle-irons to form a box with inside dimensions of #ah by #ah by #bd in4 ,the box is placed on a stand at such a height that the observation windows are on a level with the observer's eye 7,fig4 #b1 ,plate ,,xi71 and it is connected1 by a gas-pipe1 with a supply of natural gas which can be measured by a gas-holder or meter alongside the box4 ,by the use of this apparatus the effect of explosive gas on flames1 of electric sparks on explosive mixtures of gas and air1 and of breaking electric lamps in an explosive mixture of gas and air1 may be studied4 ,the safety lamps are introduced into the box from beneath1 through a hole #f in4 square1 covered with a hinged iron lid1 admission to which is had through a flexible rubber sleeve1 #bj in4 long4 ,the behavior of the standard safety lamp and of the safety lamps undergoing test may be compared in this box as to height of flame for different percentages of methane in the air1 the effect of such flames in igniting gas1 etc4 ,in each end of the box is an opening #a ft4 square1 over which may be placed a paper diaphragm held by skeleton doors1 the purpose of which is to confine the gas in such a manner that1 should an explosion occur1 no damage would be done4 ,in the front of the box are two plate-glass observing windows1 #b by #e in4 ,in the side of the box1 between the two windows1 is a -in4 hole1 which can be closed by a tap-screw1 through which samples for chemical analysis are drawn4 ,the gasometer consists of two iron cans1 the lower one being open at the top and filled with water and the upper one open at the bottom and suspended by a counterweight4 ,the latter has attached to its upper surface a scale which moves with it1 thereby measuring the amount of gas in the holder4 ,a two-way cock permits the admission of gas into the gasometer and thence into the testing box4 ,gas-and-,dust ,gallery ,no4 #b4--,this gallery is constructed of sheet steel and is similar to ,gallery ,no4 #a1 the length1 however1 being only #cj ft4 and the diameter #aj ft4 ,it rests on a concrete foundation 7,fig4 #c1 ,plate ,x74 ,diaphragms can be placed across either extremity1 or at various sections1 to confine the mixtures of gas and air in which the tests are made4 ,the admission of gas is controlled by pipes and valves1 and the gas and air can be stirred or mixed by a fan1 as described for ,gallery ,no4 #a1 and as shown by ,fig4 #a4 ,gallery ,no4 #b is used for investigating the effect of flames of various lamps1 of electric currents1 motors1 and coal-cutting machines1 in the presence of known mixtures of explosive gas and air4 ,it is also used for testing the length of flame of safety lamps in still air carrying various proportions of methane1 and1 for this purpose1 is more convenient than the lamp gallery4 ,in tests with explosive mixtures1 after the device to be tested has been introduced and preparations are completed1 operations are controlled from a safe distance by a switch-board in a building near-by4 ,among other investigations conducted in this gallery are those of the effect of sparks on known gas mixtures4 ,these sparks are such as those struck from a pick on flint1 but in this case they are produced by rubbing a rapidly revolving emery wheel against a steel file4 ,the effect of a spark produced by a short circuit of known voltage1 the flame from an arc lamp1 etc41 may also be studied in this gallery4 ,,structural ,,materials ,,investigations4 ,the structural materials investigations are being conducted for the purpose of determining the nature and extent of the materials available for use in the building and construction work of the ,government1 and how these materials may be used most efficiently4 ,these investigations include3 7#a74--;,inquiries into the distribution and local availability1 near each of the building centers in the ,united ,states1 of such materials as are needed by the ,government4 7#b74--;,how these materials may be used most efficiently4 7#c74--,their fire-resisting qualities and strength at different temperatures4 7#d74--,the best and most economic methods of protecting steel by fire-resistant covering4 7#e74--,the most efficient methods of proportioning and mixing the aggregate1 locally available1 for different purposes4 7#f74--,the character and value of protective coatings1 or of various mixes1 to prevent deterioration by sea water1 alkali1 and other destructive agencies4 7#g74--,the kinds and forms of reinforcement for concrete necessary to secure the greatest strength in beams1 columns1 floor slabs1 etc4 7#h74--;,investigation of the clays and of the products of clays needed in ,government works1 as to their strength1 durability1 suitability as fire-resisting materials1 and the methods of analyzing and testing clay products4 7#i74--,tests of building stones1 and investigations as to their availability near the various building centers throughout the ,united ,states4 ,the operations of the ,structural ,materials ,division include investigations into cement-making materials1 constituent materials of concrete1 building stones1 clays1 clay products1 iron1 steel1 and miscellaneous materials of construction1 for the use of the ,government4 ,the organization comprises a number of sections1 including those for the chemical and physical examination of ,departmental purchases2 field sampling and laboratory examination of constituent materials of concrete collected by skilled field inspectors in the neighborhood of the larger commercial and building centers2 similar field sampling of building stones and of clays and clay products1 offered for use in ,government buildings or engineering construction2 and the forwarding of such samples to the testing laboratories at ,st4 ,louis or ,pittsburg for investigation and test4 ,the investigative tests include experiments regarding destructive agencies1 such as electrolysis1 alkaline earths and waters1 salt water1 fire1 and weathering2 also experiments with protective and water-proofing agencies1 including the various washes or patented mixtures on the market1 and the methods of washing1 and mixing mortars and concrete1 which are likely to result in rendering such materials less pervious to water4 ,investigations are also being conducted to determine the nature and extent of materials available for use in the building-construction work of the ,government1 and how these materials may be used most efficiently and safely4 ,while the act authorizing this work does not permit investigations or tests for private parties1 it is believed that these tests for the ,government cannot fail to be of great general value4 ,the aggregate expenditure by the ,federal ,government in building and engineering construction is about #dj1jjj1jjj annually4 ,this work is being executed under so many different conditions1 at points so widely separated geographically1 and requires so great a variety of materials1 that the problems to be solved for the ,government can hardly fail to cover a large share of the needs of the ,engineering ,profession1 ,state and municipal governments1 and the general public4 ,character of the ,work4--,the tests and analyses1 of the materials of construction purchased by the various bureaus and departments for the use of the ,government1 are to determine the character1 quality1 suitability1 and availability of the materials submitted1 and to ascertain data leading to more accurate working values as a basis for better working specifications1 so as to enable ,government officials to use such materials with more economy and increased efficiency4 ,investigative tests of materials entering into ,government construction1 relative to the larger problems involved in the use of materials purchased by the ,government1 include exhaustive study of the suitability for use1 in concrete construction on the ,isthmian ,canal1 of the sand and stone1 and of the cementing value of pozzuolanic material1 found on the ,isthmus2 the strength1 elasticity1 and chemical properties of structural steel for canal lock-gates2 of wire rope and cables for use in hoisting and haulage2 and the most suitable sand and stone available for concrete and reinforced concrete for under-water construction1 such as the retaining walls being built by the ,quartermaster's ,department of the ,army1 in ,san ,francisco ,harbor4 ,these tests also include investigations into the disintegrating effect of alkaline soil and water on the concrete and reinforced concrete structures of the ,reclamation ,service1 with a view to preventing such disintegration2 investigations into the proper proportions and dimensions of concrete and reinforced concrete structural columns1 beams1 and piers1 and of walls of brick and of building stone1 and of the various types of metal used for reinforcement by the ,supervising ,architect in the construction of public buildings2 investigations into the sand1 gravel1 and broken stone available for local use in concrete construction1 such as columns1 piers1 arches1 floor slabs1 etc41 as a guide to the more economical design of public structures1 and to determine the proper method of mixing the materials to render the concrete most impervious to water and resistant to weather and other destructive agencies4 ,other lines of research may be stated briefly as follows3 ,the extent to which concrete made from cement and local materials can be most safely and efficiently used for different purposes under different conditions2 ,the best methods for mixing and utilizing the various constituent materials locally available for use in ,government construction2 ,the materials suitable for the manufacture of cement on the public lands1 or where the ,government has planned extensive building or engineering construction work1 where no cement plants now exist2 ,the kinds and forms of reinforcement for concrete1 and the best methods of applying them in order to secure the greatest strength in compression1 tension1 shear1 etc41 in reinforced concrete beams1 columns1 floor slabs1 etc42 ,the influence of acids1 oils1 salts1 and other foreign materials1 long-continued strain1 or electric currents1 on the permanence of the steel in reinforced concrete2 ,the value of protective coatings as preventives of deterioration of structural materials by destructive agencies2 and ,the establishment of working stresses for various structural materials needed by the ,government in its buildings4 ,investigations are being made into the effects of fire and the rate of conductivity of heat on concrete and reinforced concrete1 brick1 tile1 building stone1 etc41 as a guide to the use of the most suitable materials for fire-proof building construction and the proper dimensioning of fire-resistive coverings4 ,investigations and tests are being made1 with a view to the preparation of working specifications for use in ,government construction1 of bricks1 tile1 sand-lime brick1 paving brick1 sewer pipe1 roofing slates1 flooring tiles1 cable conduits1 electric insulators1 architectural terra cotta1 fire-brick1 and all shapes of refractories and other clay products1 regarding which no satisfactory data for the preparation of specifications of working values now exist4 ,investigations of the clay deposits throughout the ,united ,states are in progress1 to determine proper methods of converting them into building brick1 tile1 etc41 at the most reasonable cost1 and the suitability of the resulting material for erection in structural forms and to meet building requirements4 ,investigations are being made in the field1 of building stones locally available1 and physical and chemical tests of these building stones to determine their bearing or crushing strength2 the most suitable mortars for use with them2 their resistance to weathering2 their fire-resistive and fire-proof qualities1 etc41 regarding which practically no adequate information is available as a guide to ,government engineering and building design4 ,results ,accomplished4--,during one period of six months alone1 more than #b1ejj samples1 taken from ,government purchases of structural materials1 were examined1 of which more than #cjj failed to meet the specified requirements1 representing many thousands of dollars worth of inferior material rejected1 which otherwise would have been paid for by the ,government4 ,these tests were the means of detecting the inferior quality of large quantities of materials delivered on contracts1 and the moral effect on bidders has proven as important a factor in the maintenance of a high quality of purchases1 as in the saving of money4 ,the examination of sands1 gravels1 and crushed stones1 as constituent materials for concrete and reinforced concrete construction1 has developed data showing that certain materials1 locally available near large building centers and previously regarded as inferior in quality1 were1 in fact1 superior to other and more expensive materials which it had been proposed to use4 ,these investigations have represented an actual saving in the cost of construction on the work of the ,isthmian ,canal ,commission1 of the ,supervising ,architect1 and of certain ,states and cities which have benefited by the information disseminated regarding these constituent materials4 ,investigations of clay products1 only recently inaugurated1 have already resulted in the ascertainment of important facts relative to the colloid matter of clay and its measurement1 and the bearing thereof on the plasticity and working values of various clays4 ,the study of the preliminary treatment of clays difficult to handle dry1 has furnished useful information regarding the drying of such clays1 and concerning the fire resistance of bricks made of soft1 stiff1 or dried clay of various densities4 ,the field collection and investigation of building-stone samples have developed some important facts which had not been considered previously1 relative to the effect of quarrying1 in relation to the strike and dip of the bedding planes of building stone1 and the strength and durability of the same material when erected in building construction4 ,these investigations have also developed certain fundamental facts relative to the effects of blasting 7as compared with channeling or cutting7 on the strength and durability of quarried building stone4 ,mineral ,chemistry ,laboratories4--,investigations and analyses of the materials of engineering and building construction are carried on at ,pittsburg in four of the larger rooms of ,building ,no4 #ba4 ,in this laboratory1 are conducted research investigations into the effect of alkaline waters and soils on the constituent materials of concrete available in arid regions1 as related to the life and permanency of the concrete and reinforced concrete construction of the ,reclamation ,service4 ,these investigations include a study of individual salts found in particular alkalis1 and a study of the results of allowing solutions of various alkalis to percolate through cylinders of cement mortar and concrete4 ,other research analyses have to do with the investigation of destructive and preservative agencies for concrete1 reinforced concrete1 and similar materials1 and with the chemistry of the effects of salt water on concrete1 etc4 ,the routine chemical analyses of the constituent materials of concrete and cement-making materials1 are made in this laboratory1 as are also a large number of miscellaneous chemical analyses and investigations of reinforcement metal1 the composition of building stones1 and allied work4 ,a heat laboratory1 in charge of ,dr4 ,j4 ,k4 ,clement1 occupies three rooms on the ground floor of ,building ,no4 #ba1 and is concerned chiefly with the measurement of temperatures in gas producers1 in the furnaces of steam boilers1 kilns1 etc4 ,the work includes determinations of the thermal conductivity of fire clays1 concrete1 and other building materials1 and of their fire-resisting properties2 measurements of the thermal expansion and specific heats of fire-bricks1 porcelain1 and glazes2 and investigations of the effect of temperature variations on the various chemical processes which take place in the fuel bed of the gas producer1 boiler furnace1 etc4 ,the heat laboratory is equipped for the calibration of the thermometers and pyrometers1 and electrical and other physical apparatus used by the various sections of the ,technologic ,branch4 ,for convenience in analyzing materials received from the various purchasing officers attached to the ,government bureaus1 this work is housed in a laboratory on the fourth floor of the ,geological ,survey ,building in ,washington4 ,large quantities and many varieties of building materials for use in public buildings under contract with the ,supervising ,architect's office1 are submitted to the laboratory by contractors to determine whether or not they meet the specified requirements4 ,further examinations are made of samples submitted by superintendents of construction1 representing material actually furnished by contractors4 ,it is frequently found that the sample of material submitted by the contractor is of far better quality than that sent by the superintendent to represent deliveries4 ,the needed constant check on deliveries is thus provided4 ,in addition to this work for the office of the ,supervising ,architect1 similar work on purchases and supplies is carried on for the ,isthmian ,canal ,commission1 the ,quartermaster-,general's ,department of the ,army1 the ,life ,saving ,service1 the ,reclamation ,service1 and other branches of the ,government4 ,about #cjj samples are examined each month1 requiring an average of #ab determinations per sample1 or about #c1fjj determinations per month4 ,the chemical laboratory for testing ,government purchases of structural materials is equipped with the necessary apparatus for making the requisite physical and chemical tests4 ,for the physical tests of cement1 there are a tensile test machine1 briquette moulds1 a pat tank for boiling tests to determine soundness1 water tanks for the storage of briquettes1 a moist oven1 apparatus to determine specific gravity1 fineness of grinding1 etc4 ,the chemical laboratory at ,washington is equipped with the necessary analytical balances1 steam ovens1 baths1 blast lamps1 stills1 etc41 required in the routine chemical analysis of cement1 plaster1 clay1 bricks and terra cotta1 mineral paints and pigments1 roofing material1 tern plate and asphaltic compounds1 water-proofing materials1 iron and steel alloys1 etc4 ,at present1 materials which require investigative tests as a basis for the preparation of suitable specifications1 tests not connected with the immediate determination as to whether or not the purchases are in accordance with the specifications1 are referred to the chemical laboratories attached to the ,structural ,materials ,division1 at ,pittsburg4 ,the inspection and tests of cement purchased in large quantities1 such as the larger purchases on behalf of public-building construction under the ,supervising ,architect1 or the great #d1ejj1jjj-;bbl4 contract of the ,isthmian ,canal ,commission1 are made in the cement-testing laboratory of the ,survey1 in the ,lehigh ,portland cement district1 at ,northampton1 ,pa4 ,testing ,machines4--,the various structural forms into which concrete and reinforced concrete may be assembled for use in public-building construction1 are undergoing investigative tests as to their compressive and tensile strength1 resistance to shearing1 modulus of elasticity1 coefficient of expansion1 fire-resistive qualities1 etc4 ,similar tests are being conducted on building stone1 clay products1 and the structural forms in which steel and iron are used for building construction4 ,the compressive1 tensile1 and other large testing machines1 for all kinds of structural materials reaching the testing stations1 are under the general supervision of ,richard ,l4 ,humphrey1 ,m4 ,am4 ,soc4 ,c4 ,e4 ,the immediate direction of the physical tests on the larger testing machines is in charge of ,mr4 ,h4 ,h4 ,kaplan4 ,most of this testing apparatus1 prior to #aiji1 was housed in buildings loaned by the ,city of ,st4 ,louis1 in ,forest ,park1 ,st4 ,louis1 ,mo41 and the arrangement of these buildings1 details of equipment1 organization1 and methods of conducting the tests1 are fully set forth in ,bulletin ,no4 #cbi of the ,u4,s4 ,geological ,survey4 ,in brief1 this equipment included motor-driven1 universal1 four-screw testing machines1 as follows3 ,one #fjj1jjj-lb41 vertical automatic1 four-screw machine2 one #bjj1jjj-lb41 automatic1 four-screw machine2 and one #bjj1jjj-lb4 and one #ajj1jjj-lb4 machine of the same type1 but with three screws4 ,there are a number of smaller machines of #ej1jjj1 #dj1jjj1 #aj1jjj1 and #b1jjj lb41 respectively4 ,these machines are equipped so that all are available for making tensile and compressive tests 7,fig4 #a1 ,plate ,,xiii74 ,the #fjj1jjj-lb4 machine is capable of testing columns up to #cj-;ft4 lengths1 and of making transverse tests of beams up to #be-;ft4 span1 and tension tests for specimens up to #bd ft4 in length4 ,the smaller machines are capable of making tension and compressive tests up to #d ft4 in length and transverse beam tests up to #ab ft4 span4 ,in addition1 there are ample subsidiary apparatus1 including concrete mixers with capacities of and #a cu4 yd41 five hollow concrete block machines1 automatic sifting machines1 briquette moulds1 storage tanks1 etc4 ,at the ,atlantic ,city sub-station1 there is also a #bjj1jjj-lb41 universal1 four-screw testing machine1 with miscellaneous equipment for testing cement and moulding concrete1 etc42 and at the ,northampton sub-station1 there is a complete equipment of apparatus for cement testing1 capable of handling #aj1jjj bbl4 per day4 ,at the ,pittsburg testing station1 a #aj1jjj1jjj-lb41 vertical1 compression testing machine 7,plate ,,xiv71 made by ,tinius ,olsen and ,company1 is being erected for making a complete series of comparative tests of various building stones of #b1 #d1 and #ab-;in4 cube1 of stone prisms1 #ab in4 base and #bd in4 high1 of concrete and reinforced concrete columns up to #fe ft4 in height1 and of brick piers and structural-steel columns up to the the limits of the capacity and height of the machine4 ,illustration3 ,,plate ,,xiii4 ,fig4 #a4--,testing ,beam in #bjj1jjj-,lb4 ,machine4 ,fig4 #b4--;,fire ,test of ,panel4 ,this machine is a large hydraulic press1 with an adjustable head1 and a weighing system for recording the loading developed by a triple-plunger pump4 ,it has a maximum clearance of #fe ft4 between heads2 the clearance in the machine is a trifle more than #f ft4 between screws1 and the heads are #f ft4 square4 ,the machine consists of a base containing the main cylinder1 with a sectional area of #b1jjj sq4 in41 upon which rests the lower platform or head1 which is provided with a ball-and-socket bearing4 ,the upper head is adjustable over four vertical screws1 #ac in4 in diameter and #gb ft4 #b in4 long1 by a system of gearing operating four nuts with ball-bearings upon which the head rests4 ,the shafting operating this mechanism is connected with a variable-speed motor which actuates the triple-plunger pump supplying the pressure to the main cylinder 7,fig4 #d74 ,the weighing device consists of a set of standard ,olsen levers for weighing one-eightieth of the total load on the main cylinder4 ,this reduction is effected through the medium of a piston and a diaphragm4 ,the main cylinder has a diameter of #ej in41 and the smaller one1 a diameter of #e-i_/af in4 ,the weighing beam is balanced by an automatically-operated poise weight1 and is provided with a device for applying successive counterweights of #a1jjj1jjj lb4 each4 ,each division on the dial is equivalent to a #ajj-lb4 load1 and smaller subdivisions are made possible by an additional needle-beam4 ,the power is applied by a #ae-;h4p41 #bbj-volt1 variable-speed motor operating a triple-plunger pump1 the gearing operating the upper head being driven by the same motor4 ,the extreme length of the main screws necessitates splicing1 which is accomplished as follows3 ,in the center of the screws1 at the splice1 is a #c-;in4 threaded pin for centering the upper and lower screws2 this splice is strengthened by sleeve nuts1 split to facilitate their removal whenever it is necessary to lower the upper head2 after the head has passed the splice1 the sleeve nuts are replaced4 ,in order to maintain a constant load1 a needle-valve has been provided1 which1 when the pump is operated at its lowest speed1 will allow a sufficient quantity of oil to flow into the main cylinder to equalize whatever leakage there may be4 ,the main cylinder has a vertical movement of #bd in4 ,the speed of the machine1 for the purpose of adjustment1 using the gearing attached to the upper head1 is #aj in4 per min4 ,the speed for applying loads1 controlled by the variable-speed motor driving the pump1 varies from a minimum of at least #a_/fj in4 per min4 to a maximum of at least in4 per min4 ,the machine has a guaranteed accuracy of at least one-third of #a1 for any load of more than #ajj1jjj lb41 up to its capacity4 ,illustration3 ,fig4 #d4 ,,plan ,,and ,,elevation ,,of #aj1jjj1jjj-,,lb4 ,,vertical ,,compression ,,testing ,,machine ,the castings for the base and the top head weigh approximately #dh1jjj lb4 each4 ,each main screw weighs more than #dj1jjj lb41 the lower platform weighing about #be1jjj lb41 and the main cylinder1 #af1jjj lb4 ,the top of the machine will be about #gj ft4 above the top of the floor1 and the concrete foundation1 upon which it rests1 is about #h ft4 below the floor line4 ,illustration3 ,,plate ,,xiv4 #aj1jjj1jjj-,lb4 ,testing ,machine4 ,concrete and ,cement ,investigations4--,the investigations relating to concrete include the examination of the deposits of sand1 gravel1 stone1 etc41 in the field1 the collection of representative samples1 and the shipment of these samples to the laboratory for analysis and test4 ,these tests are conducted in connection with the investigation of cement mortars1 made from a typical ,portland cement prepared by thoroughly mixing a number of brands1 each of which must meet the following requirements3 ,specific gravity1 not less than #c4aj2 ,fineness1 residue not to exceed #h on ,no4 #ajj1 nor #be on ,no4 #bjj sieve2 ,time of setting3 ,initial set1 not less than #cj min42 hard set1 not less than #a hour1 nor more than #aj hours4 ,tensile strength3 ,requirements applying to neat cement and to #a part cement with #c parts standard sand3 ---------------------------------------- --------------- ,neat cement4 #a3c ,mix4 ,time specification4 ,pounds4 ,pounds4 ---------------------------------------- --------------- #bd hours in moist air #age 444 #g days 7#a day in moist air1 #ejj #age #f days in water7 #bh days 7#a day in moist air1 #fjj #bej #bg days in water7 ---------------------------------------- --------------- ,constancy of volume3 ,pats of neat cement1 #c in4 in diameter1 in4 thick at center1 tapering to a thin edge1 shall be kept in moist air for a period of #bd hours4 ,a pat is kept in air at normal temperature and observed at intervals for at least #bh days4 ,another pat is kept in water maintained as near #gj ,fahr4 as practicable1 and is observed at intervals for at least #bh days4 ,a third pat is exposed in an atmosphere of steam above boiling water1 in a loosely-closed vessel1 for #e hours4 ,these pats must remain firm and hard and show no signs of distortion1 checking1 cracking1 or disfiguration4 ,the cement shall not contain more than #a4ge of anhydrous sulphuric acid1 nor more than #d of magnesium oxide4 ,a test of the neat cement must be made with each mortar series for comparison of the quality of the typical ,portland cement4 ,the constituent materials are subjected to the following examination and determinations1 and1 in addition1 are analyzed to determine the composition and character of the stone1 sand1 etc43 #a4--,mineralogical examination1 #b4--,specific gravity1 #c4--,weight1 per cubic foot1 #d4--,sifting 7granulometric composition71 #e4--,percentage of silt and character of same1 #f4--,percentage of voids1 #g4--;,character of stone as to percentage of absorption1 porosity1 permeability1 compressive strength1 and behavior under treatment4 ,physical tests are made to determine the tensile1 compressive1 and transverse strengths of the cement and mortar test pieces1 with various preparations of cement and various percentages of material4 ,tests are also made to determine porosity1 permeability1 volumetric changes in setting1 absorption1 coefficient of expansion1 effect of oil1 etc4 ,investigation of concretes made from mixtures of typical ,portland cement1 sand1 stone1 and gravel1 includes tests on cylinders1 prisms1 cubes1 and other standard test pieces1 with various proportions of materials and at ages ranging from #cj to #cfj days4 ,full-sized plain concrete beams1 moulded building blocks1 reinforced concrete beams1 columns1 floor slabs1 arches1 etc41 are tested to determine the effect1 character1 and amount of reinforcement1 the effect of changes in volume1 size1 and composition1 and the effect of different methods of loading and of supporting these pieces1 etc4 ,these investigations include detailed inquiry in the field and research in the chemical and physical laboratories regarding the effects of alkaline soils and waters on structures of concrete being built by the ,reclamation ,service in the arid regions4 ,it has been noted that on certain of the ,reclamation projects1 notably on the ,sun ,river ,project1 near ,great ,falls1 ,mont41 the ,shoshone ,project1 near ,cody1 ,wyo41 and the ,carlsbad and ,hondo ,projects in the ,pecos ,valley1 ,n4 ,mex41 structures of concrete1 reinforced concrete1 building stones1 brick1 and tile1 show evidence of disintegration4 ,this is attributed to the effects of alkaline waters or soils coming into contact with the structures1 or to the constituent materials used4 ,in co-operation with the ,reclamation ,service1 samples of the waters1 soils1 and constituent materials1 are collected in the field1 and are subjected to careful chemical examination in the mineral laboratories at ,pittsburg4 ,illustration3 ,,plate ,,xv4 ,fig4 #a4--;,characteristic ,failures of ,reinforced ,concrete ,beams4 ,fig4 #b4--;,arrangement of ,static ,load ,test for ,reinforced ,concrete ,beams4 ,the cylinders used in the percolation tests are composed of typical ,portland cement mixed with sand1 gravel1 and broken stone of known composition and behavior1 and of cement mixed with sand1 gravel1 and broken stone collected in the neighborhood of the ,reclamation projects under investigation4 ,illustration3 ,fig4 #e4 ,,cross-,,section ,,of ,,apparatus ,,for ,,holding ,,permeability-,,test ,,pieces ,it is also proposed to subject these test pieces1 some made with water of known purity1 and others with alkaline water1 to contact with alkaline soils near the projects1 and with soil of known composition near the testing laboratories at ,pittsburg4 ,as these tests progress and other lines of investigation are developed1 the programme will be extended1 in the hope that the inquiry may develop methods of preparing and mixing concrete and reinforced concrete which can be used in alkaline soils without danger of disintegration4 ,investigations into the effect of salt water on cement mortars and concretes1 and the effect of electrolysis1 are being conducted at ,atlantic ,city1 ,n4,j41 where the test pieces may be immersed in deep sea water for longer or shorter periods of time4 ,at the ,pittsburg laboratory a great amount of investigative work is done for the purpose of determining the suitability and availability of various structural materials submitted for use by the ,government4 ,while primarily valuable only to the ,government1 the results of these tests are of indirect value to all who are interested in the use of similar materials4 ,among such investigations have been those relating to the strength1 elasticity1 and chemical properties of wire rope for use in the ,canal ,zone2 investigations of the suitability and cementing value of concrete1 sand1 stone1 and pozzuolanic material found on the ,isthmus2 investigations as to the relative resistance to corrosion of various types of wire screens for use in the ,canal ,zone2 into the suitability for use1 in concrete sea-wall construction1 of sand and stone from the vicinity of ,san ,francisco2 into the properties of reinforced concrete floor slabs2 routine tests of reinforcing metal1 and of reinforced concrete beams and columns1 for the ,supervising ,architect of the ,treasury ,department1 etc4 ,the results have been set forth in three bulletins#i which describe the methods of conducting these tests and also tests on constituent materials of concrete and plain concrete beams4 ,in addition1 there are in process of publication a number of bulletins giving the results of tests on reinforced concrete beams1 columns1 and floor slabs1 concrete building blocks1 etc4 ,the ,northampton laboratory was established because it is in the center of the ,lehigh cement district1 and therefore available for the mill sampling and testing of purchases of cement made by the ,isthmian ,canal ,commission2 it is also available for tests of cement purchased in the ,lehigh district by the ,supervising ,architect and others4 ,it is in a building1 the outer walls of which are of cement plaster applied over metal lath nailed to studding4 ,the partitions are of the same construction1 and the floors and roof are of concrete throughout4 ,the inspection at the factories and the sampling of the cement are under the immediate direction of the ,commission2 the testing is under the direction of the ,u4,s4 ,geological ,survey4 ,a large force of employees is required1 in view of the magnitude of the work1 which includes the daily testing of consignments ranging from #e1jjj to #aj1jjj bbl41 sampled in lots of #ajj bbl41 which is equivalent to from #ej to #ajj samples tested per day4 ,the cement to be sampled is taken from the storage bins and kept under seal by the chief inspector pending the results of the test4 ,the quantity of cement sampled is sufficient for the tests required under the specifications of the ,isthmian ,canal ,commission1 as well as for preliminary tests made by the cement company1 and check tests made at the ,geological ,survey laboratory1 at ,pittsburg4 ,the tests specified by the ,commission include determination of specific gravity1 fineness of grinding1 time of setting1 soundness1 tensile strength 7with three parts of standard quartz sand for #g and #bh days1 respectively71 and determination of sulphur anhydride 7,,so#c71 and magnesia 7,mg,o74 ,the briquette-making and testing room is fitted with a mixing table1 moist closet1 briquette-storage tanks1 and testing machines4 ,the mixing table has a concrete top1 in which is set plate glass1 #ah in4 square and #a in4 thick4 ,underneath the table are shelves for moulds1 glass plates1 etc4 ,the moist closet1 #e ft4 high1 #c ft4 #aj in4 wide1 and #a ft4 #h in4 deep1 is divided into two compartments by a vertical partition1 and each compartment is fitted with cleats for supporting thirteen tiers of glass plates4 ,on each pair of cleats1 in each compartment1 can be placed four glass plates1 each plate containing a #d-;gang mould1 making storage for #daf briquettes4 ,with the exception of the doors1 which are of wood lined with copper1 the closet is of #a3a cement mortar1 poured monolithic1 even to the cleats for supporting the glass plates4 ,the immersion tanks1 of the same mortar1 are in tiers of three1 supported by a steel structure4 ,they are #f ft4 long1 #b ft4 wide1 and #f in4 deep1 and #b1jjj briquettes can be stored in each tank4 ,the overflow from the top tank wastes into the second1 which1 in turn1 wastes into the third4 ,water is kept running constantly4 ,the briquette-testing machine is a ,fairbanks shot machine with a capacity of #b1jjj lb41 and is regulated to apply the load at the rate of #fjj lb4 per min4 ,twenty-four #d-;gang moulds1 of the type recommended by the ,special ,committee on ,uniform ,tests of ,cement1 of the ,american ,society of ,civil ,engineers1 are used4 ,the room for noting time of set and soundness is fitted with a mixing table similar to that in the briquette-making room4 ,the ,vicat apparatus is used for determining the normal consistency1 and the ,gilmore apparatus for the time of setting4 ,while setting1 the soundness pats are stored in galvanized-iron pans having about #a in4 of water in the bottom1 and covered with dampened felt or burlap4 ,the pats rest on a rack slightly above the water and well below the felt4 ,for specific gravity tests1 the ,le ,chatelier bottles are used4 ,a pan1 in which five bottles can be immersed at one time1 is used for maintaining the benzine at a constant temperature4 ,the samples are weighed on a pair of ,troemner's ,no4 #g scales4 ,the fineness room is fitted with tables1 two sets of standard ,no4 #ajj and ,no4 #bjj sieves1 and two ,troemner's ,no4 #g scales similar to those used for the specific gravity tests4 ,the storage room is fitted with shelves for the storage of samples being held for #bh-;day tests4 ,the mould-cleaning room contains tables for cleaning moulds1 and racks for air pats4 ,an effort is made to keep all the rooms at a temperature of #gj ,fahr41 and1 with this in view1 a ,bristol recording thermometer is placed in the briquette-room4 ,two wet-and-dry bulb hygrometers are used to determine the moisture in the air4 ,samples are taken from the conveyor which carries the cement to the storage bins1 at the approximate rate of one sample for each #ajj bbl4 ,after each #d1jjj-;bbl4 bin has been filled1 it is sealed until all tests have been made1 when1 if these have been satisfactory1 it is released for shipment4 ,the samples are taken in cans1 #i in4 high and #g in4 in diameter4 ,these cans are delivered in the preparation room where the contents are mixed and passed through a ,no4 #bj sieve4 ,separate samples are then weighed out for mortar briquettes1 for soundness pats1 and for the specific-gravity and fineness tests4 ,these are placed in smaller cans and a quantity sufficient for a re-test is held in the storage room awaiting the results of all the tests4 ,the sample for briquettes is mixed with three parts standard crushed quartz1 and then taken to the briquette-making room1 where eight briquettes are made1 four for #g-;day and four for #bh-;day tests4 ,these are placed in the moist closet in damp air for #bd hours1 then removed from the moulds1 and placed in water for the remainder of the test period4 ,at the proper time they are taken from the immersion tank and broken4 ,from the sample for soundness1 four pats are made4 ,the time of setting is determined on one of these pats4 ,they are placed in the pan previously described1 for #bd hours1 then one is placed in running water and one in air for #bh days4 ,the others are treated in the boiler1 one in boiling water for #c hours and one in steam at atmospheric pressure for #e hours4 ,the sample taken for specific gravity and fineness is dried in the oven at #ajj cent4 in order to drive off moisture4 ,two samples are then carefully weighed out1 #ej grammes for fineness and #fd grammes for specific gravity1 and the determinations are made4 ,as soon as anything unsatisfactory develops1 a re-test is made4 ,if1 however1 the cement satisfies all requirements1 a report sheet containing all the data for a bin1 is made out1 and the cement is ready for shipment4 ,from every fifth bin1 special neat and mortar briquettes are made1 which are intended for tests at ages up to ten years4 ,salt-,water ,laboratory4--,the laboratory at ,atlantic ,city1 for conducting investigations into the effects of salt water on concrete and reinforced concrete1 is situated so that water more than #be ft4 deep is available for immersion tests of the setting and deterioration of such materials4 ,through the courtesy of the municipality of ,atlantic ,city1 ,young's cottage1 on old ,young's ,pier1 has been turned over1 at a nominal rental1 to the ,geological ,survey for the conduct of these tests4 ,the laboratory building is about #gjj ft4 from the boardwalk1 and occupies a space about #ajj by #de ft4 ,it is one story high1 of frame-cottage construction1 and stands on wooden piles at one side of the pier proper and about #bj ft4 above the water1 which is about #ai ft4 deep at this point4 ,fresh running water1 gas1 electric light1 and electric power are supplied to the building 7,fig4 #f74 ,in this laboratory investigations will be made of the cause of the failure and disintegration of cement and concrete subjected to the action of sea water4 ,tests are conducted so as to approach1 as nearly as possible1 the actual conditions found in concrete construction along the sea coast4 ,all sea-water tests are made in the ocean1 some will probably be paralleled by ocean-water laboratory tests and all by fresh-water comparative tests4 ,cements1 in the form of pats1 briquettes1 cubes1 cylinders1 and in a loose ground state1 and also mortars and concretes in cube1 cylinder1 and slab form1 are subjected to sea water4 ,the general plan for the investigations is as follows3 #a4--;,determination of the failing elements and the nature of the failure2 #b4--;,determination of the value of the theories advanced at the present time2 and1 #c4--;,determination of a method of eliminating or chemically recombining the injurious elements4 ,preliminary tests are in progress1 including a study of the effect of salt water on mortars and concretes of various mixtures and ages4 ,the proportions of these mixtures and the methods of mixing will be varied from time to time1 as suggested by the progress of the tests4 ,fire-,proofing ,tests4--,tests of the fire-proofing and fire-resistive properties of various structural materials are carried on in the laboratories in ,building ,no4 #aj1 at ,pittsburg1 and in co-operation with the ,board or ,fire ,underwriters at its ,chicago laboratory 7,fig4 #b1 ,plate ,,xiii74 ,these tests include three essential classes of material3 7a71 clay products1 protective coverings representative of numerous varieties of brick and fire-proofing tiles1 including those on the market and those especially manufactured for these tests in the laboratory at ,pittsburg2 7b71 characteristic granites of ,new ,england1 with subsequent tests of the various building stones found throughout the ,united ,states2 and 7c71 cement and concrete covering material1 building blocks1 and concrete reinforced by steel bars embedded at different depths for the purpose of studying the effect of expansion on the protective covering4 ,in co-operation with the physical laboratory1 these tests include a study of the relative rates of conductivity of cement mortars and concretes4 ,by embedding thermo-couples in cylinders composed of the materials under test1 obtaining a given temperature by an electric coil1 and noting the time required to raise the temperature at the various embedded couples to a given degree1 the rate of conductivity may be determined4 ,other tests include those in muffles to determine the rate of expansion and the effect of heat and compressive stresses combined on the compressive strength of the various structural materials4 ,the methods of making the panel tests1 and the equipment used1 are described and illustrated in ,bulletin ,no4 #cbi1 and the results of the tests have been published in detail4#aj ,building ,stones ,investigations4--,the field investigations of building stones are conducted by ,mr4 ,e4 ,f4 ,burchard1 and include the examination of the various deposits found throughout the ,united ,states4 ,a study of the granites of ,new ,england has been commenced1 which includes the collection of type specimens of fine1 medium1 and coarse-grained granites1 and of dark1 medium1 and light-gray or white granites4 ,a comparative series of these granites1 consisting of prisms and cubes of #d and #b in41 respectively1 has been prepared4 ,illustration3 ,fig4 #f4 ,,plan ,,of ,,laboratory ,,for ,,salt-,,water ,,tests ,,at ,,atlantic ,,city1 ,n4,j4 ,the standard adopted for compressive test pieces in the #aj1jjj1jjj-lb4 machine is a prism1 having a base of #ab in4 and being #bd in4 high4 ,the tests include not only those for compression or crushing strength1 but also those for resistance to compressive strains of the prisms and cubes1 when raised to high temperatures in muffles or kilns2 resistance to weathering1 freezing1 and thawing2 porosity2 fire-resisting qualities1 etc4 ,in collecting field samples1 special attention is paid to the occurrence of the stone1 extent of the deposit1 strike1 dip1 etc41 and specimens are procured having their faces cut with reference to the bedding planes1 in order that compressive and weathering tests may be made1 not only in relation to these planes but at those angles thereto in which the material is most frequently used commercially4 ,attention is also paid to the results of blasting1 in its relation to compressive strains1 as blasting is believed to have a material effect on stones1 especially on those which may occur in the foundations of great masonry dams1 and type specimens of stone quarried by channeling1 as well as by blasting1 are collected and tested4 ,clay and ,clay ,products ,investigations4--,these investigations are in charge of ,mr4 ,a4 ,v4 ,bleininger1 and include the study of the occurrence of clay beds in various parts of the ,united ,states1 and the adaptability of each clay to the manufacture of the various clay products4 ,experiments on grinding1 drying1 and burning the materials are conducted at the ,pittsburg testing station1 to ascertain the most favorable conditions for preparing and burning each clay1 and to determine the most suitable economic use to which it may be put1 such as the manufacture of building or paving bricks1 architectural tiles1 sewer tiles1 etc4 ,the laboratory is equipped with various grinding and drying devices1 muffles1 kilns1 and apparatus for chemical investigations1 physical tests1 and the manufacture and subsequent investigative tests of clay products4 ,this section occupies the east end of ,building ,no4 #aj1 and rooms on the first and second floors have been allotted for this work4 ,in addition1 a brick structure1 #df by #cj ft41 provided with a #fj-;ft4 iron stack1 has been erected for housing the necessary kilns and furnaces4 ,illustration3 ,,plate ,,xvi4 ,fig4 #a4--;,brick ,machine and ,universal ,cutter4 ,fig4 #b4--;,house-,heating ,boilers1 ,building ,no4 #ba4 ,on the ground floor of ,building ,no4 #aj1 adjoining the cement and concrete section1 is a storage room for raw materials and product under investigation4 ,adjoining this room1 and connecting with it by wide doors1 is the grinding room1 containing a #e-;ft4 wet pan1 with #b1jjj-lb4 rollers1 to be used for both dry and wet grinding4 ,later1 a heavy dry pan is to be installed4 ,with these machines1 even the hardest material can be easily disintegrated and prepared4 ,in this room there is also a jaw crusher for reducing smaller quantities of very hard material1 as well as a #cj by #af-;in4 iron ball mill1 for fine grinding4 ,these machines are belted to a line shaft along the wall across the building4 ,ample sink drainage is provided for flushing and cleaning the wet pan1 when changing from one clay to another4 ,a large room adjoining is for the operation of all moulding and shaping machines1 representing the usual commercial processes4 ,at present these include an auger machine1 with a rotary universal brick and tile cutter1 ,fig4 #a1 ,plate ,,xvi1 and a set of brick and special dies1 a hand repress for paving brick1 and a hand screw press for dry pressing4 ,the brick machine is operated from the main shaft which crosses the building in this room and is driven from a #ej-;h4p4 motor4 ,it is possible thus to study the power consumption under different loads and with different clays1 as well as with varying degrees of water content in the clay4 ,as the needs of the work demand it1 other types of machines are to be installed4 ,for special tests in which pressure is an important factor it is intended to fit up one of the compression testing machines of the cement section with the necessary dies1 thus enabling the pressing to be carried on under known pressures4 ,crushing1 transverse1 and other tests of clay products are made on the testing machines of the cement and concrete laboratories4 ,outside of the building1 in a lean-to1 there is a double-chamber rattler for the testing of paving brick according to the specifications of the ,national ,brick ,manufacturers' ,association4 ,in the smaller room adjoining the machine laboratory there are two small wet-grinding ball mills1 of two and four jars1 respectively1 and also a #i-leaf laboratory filter press4 ,the remaining room on the first floor is devoted to the drying of clays and clay wares4 ,the equipment consists of a large sheet-iron drying oven of special construction1 which permits of close regulation of the temperature 7,fig4 #g74 ,it is heated by gas burners1 and is used for the preliminary heat treatment of raw clays1 in connection with the study of the drying problems of certain raw materials4 ,it is intended to work with temperatures as high as #bej cent4 ,another drying closet1 heated by steam coils 7,fig4 #h71 intended for drying various clay products1 has been designed with special reference to the exact regulation of the temperature1 humidity1 and velocity of the air flowing through it4 ,both dryers connect by flues with an iron stack outside the building4 ,this stack is provided with a suction fan1 driven by a belt from an electric motor4 ,on the second floor are the chemical1 physical1 and research laboratories1 dealing with the precise manipulations of the tests and investigations4 ,the chemical laboratory is fully equipped with the necessary apparatus for carrying on special chemical research in silicate chemistry1 including electrical resistance furnaces1 shaking devices1 etc4 ,it is not the intention to do routine work in this laboratory4 ,the office adjoins this laboratory1 and near it is the physical laboratory1 devoted to the study of the structure of raw materials4 ,the latter contains ,nobel and ,schoene elutriators1 together with viscosimeters of the flow and the ,coulomb and ,clark electrical types1 sieves1 voluminometers1 colorimeters1 vernier shrinkage gauges1 micrometers1 microscopes1 and the necessary balances4 ,the room across the hall is devoted to the study of the specific gravity1 absorption1 porosity1 permeability1 hardness1 translucency1 etc41 of burnt-clay products1 all the necessary apparatus being provided4 ,in the two remaining rooms1 intended for research work1 special apparatus adapted to the particular investigation may be set up4 ,all the rooms are piped for water1 gas1 compressed air1 steam1 and drainage1 and wired for light and power4 ,in the kiln house there is a test kiln adapted for solid fuel and gas4 ,it is of the down-draft type1 with an available burning space of about #h cu4 ft4 7,fig4 #i74 ,for heavier ware and the study of the fire behavior of clay products under conditions approaching those of practice1 a round down-draft kiln1 with an inside diameter of #f ft41 is installed4 ,about #ac ft4 above the floor level1 and supported by iron beams1 there is a flue parallel to the long side of the structure4 ,this flue conducts the gases of the kilns to the stack1 which is symmetrically located with reference to the kiln house4 ,natural gas is the principal fuel4 ,in addition to these kilns1 a small muffle furnace1 fired with petroleum1 is provided for the determination of melting points1 and an electric carbon resistance furnace1 with an aluminum muffle for high-temperature work4 ,for crucible-fusion work1 a gas-fired pot furnace is installed4 ,illustration3 ,fig4 #g4 ,,clay-,,drying ,,oven ,along the north wall1 bins are provided for the storage of fuel1 clay1 sand1 and other kiln supplies4 ,there are two floor drainage sinks1 and electric current1 steam1 water1 and compressed air1 are provided4 ,illustration3 ,fig4 #h4 ,,drying ,,closets ,,for ,,ceramics ,results of the ,work4--,more than #ci1cjj separate test pieces have been made at the structural-materials testing laboratory4 ,in connection with the study of these1 #hf1jjj tests and nearly #ad1jjj chemical analyses have been made4 ,of these tests more than #ac1fjj have been of the constituent materials of concrete1 including tensile tests of cement briquettes1 compression tests of cylinders and cubes1 and transverse tests of various specimens4 ,nearly #a1bjj beams of concrete or reinforced concrete1 each #ac ft4 long and #h by #aa in4 in cross-section1 have been made1 and1 in connection with the investigation of the behavior of these beams1 nearly #c1jjj tests have been made4 ,nearly #ijj of these beams1 probably more than double the entire number made in other laboratories in the ,united ,states1 during a period of more than #ae years1 have been tested4 ,in the section of building blocks1 #b1bjj blocks have been tested1 including1 with auxiliary pieces1 more than #d1ejj tests2 also1 more than #ijj pieces of concrete have been tested for permeability and shear4 ,the physical tests have numbered #ad1jjj2 tests of steel for reinforcement1 #c1hjj2 and #eej tests to determine fire-resistive qualities of various building materials1 have been made on #cj special panels1 and on miscellaneous pieces4 ,illustration3 ,fig4 #i4 ,,down-,,draft ,,kiln ,the tests of the permeability of cement mortars and concretes1 and of water-proofing and damp-proofing materials1 have numbered #c1dgj4 ,the results of the work of the ,structural ,materials ,division have already appeared in preliminary bulletins1 as follows3 ,no4 #cbd1 8,san ,francisco ,earthquake and ,fire of ,april #ah1 #aijf1 and ,their ,effects on ,structures and ,structural ,materials02 ,no4 #cbi1 8,organization1 ,equipment1 and ,operation of the ,structural-,materials ,testing ,laboratories at ,st4 ,louis1 ,mo402 ,no4 #cca1 8,portland ,cement ,mortars and ,their ,constituent ,materials0 7based on nearly #be1jjj tests72 ,no4 #cdd1 8,strength of ,concrete ,beams0 7based on tests of #ajh beams72 ,no4 #cgj1 8,fire-,resistive ,properties of ,various ,building ,materials02 ,no4 #chg1 8,the ,colloid ,matter of ,clay and its ,measurements40 ,a bulletin on the results of tests of reinforced concrete beams1 one on the manufacture and chemistry of lime1 and one on drying tests of brick1 are in course of publication4 ,,fuel ,,investigations4 ,the scope of the fuel investigations has been planned to conform to the provisions of the ,act of ,congress which provides for analyzing and testing coals1 lignites1 and other mineral fuel substances belonging to the ,united ,states1 or for the use of the ,united ,states ,government1 and examinations for the purpose of increasing the general efficiency or available supply of the fuel resources in the ,united ,states4 ,in conformity with this plan1 the investigations inaugurated at ,st4 ,louis had for their initial object the analyzing and testing of the coals of the ,united ,states1 using in this work samples of from #a to #c carloads1 collected with great care from typical localities in the more important coal fields of the country1 with a view to determining the relative values of those different fuels4 ,in the work at ,norfolk1 during #aijg1 this purpose was modified to the extent of keeping in view relative fuel efficiencies for naval purposes4 ,the tests at ,denver have been on coal from ,government land or from land contiguous thereto1 and are conducted solely with a view to perfecting methods of coking this coal by prior washing and by manipulation in the process of coking4 ,three general lines of inquiry are embodied in the plan of investigation undertaken and contemplated by the ,technologic ,branch1 after conference and with the advice and approval of the ,advisory ,board3 #a4 ,the ascertainment of the best mode of utilizing any fuel deposit owned or to be used by the ,government1 or the fuel of any extensive deposit as a whole1 by conducting a more thorough investigation into its combustion under steam boilers1 conversion into producer gas1 or into coke1 briquettes1 etc4 #b4 ,the prevention of waste1 through the study of the possibility of improvement in the methods of mining1 shipping1 utilizing1 etc4 #c4 ,the inspection and analysis of coal and lignite purchased under specification for the use of the ,government1 to ascertain its heating value1 ash1 contained moisture1 etc4 ,the first general line of work concerns the investigation and testing of the fuel resources of the ,united ,states1 and especially those belonging to the ,federal ,government1 to determine a more efficient and more economical method of utilizing the same4 ,this work has developed along the following lines3 ,the collection of representative samples for chemical analysis1 and calorimeter tests by a corps of skilled mine samplers1 from the mines selected as typical of extensive deposits of coal in a given field or from a given bed of coal2 and the collection from the same mines of larger samples of from #a to #c carloads1 shipped to the testing station for tests in boiler furnaces1 gas producers1 etc41 as a check on the analysis and calorimeter tests2 ,the testing of each coal received to determine the most efficient and least wasteful method of use in different furnaces suitable for public buildings or power plants or ships of the ,government2 ,the testing of other portions of the same shipment of coal in the gas producer1 for continuous runs during periods of a few days up to several weeks1 in order to determine the availability of this fuel for use in such producers1 and the best method of handling it1 to determine the conditions requisite to produce the largest amount of high-grade gas available for power purposes2 ,the testing of another portion of the same coal in a briquette machine at different pressures and with different percentages and kinds of binder1 in order to determine the feasibility of briquetting the slack or fine coal4 ,combustion tests are then made of these briquettes1 to determine the conditions under which they may be burned advantageously2 ,demonstrations1 on a commercial scale1 of the possibility of producing briquettes from ,american lignites1 and the relative value of these for purposes of combustion as compared with the run-of-mine coal from which the briquettes are made2 ,the finding of cheaper binders for use in briquetting friable coals not suited for coking purposes2 ,investigations into the distribution1 chemical composition1 and calorific value of the peat deposits available in those portions of the ,united ,states where coal is not found1 and the preparation of such peat for combustion1 by drying or briquetting1 to render it useful as a local substitute for coal2 ,investigations into the character of the various petroleums found throughout the ,united ,states1 with a view to determining their calorific value1 chemical composition1 and the various methods whereby they may be made most economically available for more efficient use as power producers1 through the various methods of combustion2 ,investigations and tests into the relative efficiency1 as power producers in internal-combustion engines1 of the heavier distillates of petroleum1 as well as of kerosene and gasoline1 in order to ascertain the commercial value and relative efficiency of each product in the various types of engines2 ,investigations into the most efficient methods of utilizing the various coals available throughout the ,united ,states for heating small public buildings1 army posts1 etc41 in order that these coals may be used more economically than at present2 ,investigative studies into the processes of combustion within boiler furnaces and gas producers to ascertain the temperatures at which the most complete combustion of the gases takes place1 and the means whereby such temperatures may be produced and maintained1 thus diminishing the loss of values up the smokestack and the amount of smoke produced2 ,investigations and tests into the possibilities of coking coals which have hitherto been classed as non-coking1 and the making of comparative tests of all coals found in the ,united ,states1 especially those from the public lands of the ,west2 ,investigations1 by means of washing in suitable machines1 to determine the possibility of improving the quality of ,american coals for various methods of combustion1 and with a view to making them more available for the production of coke of high-grade metallurgical value1 as free as possible from sulphur and other injurious substances4 ,at each stage of the process of testing1 samples of the coal have been forwarded to the chemical laboratory for analyses2 combustion temperatures have been measured2 and samples of gas collected from various parts of the combustion chambers of the gas producers and boiler furnaces have been analyzed1 in order that a study of these data may throw such light on the processes of combustion and indicate such necessary changes in the apparatus1 as might result in larger economies in the use of coal4 ,the second line of investigation concerns the methods of mining and preparing coal for the market1 and the collection of mine samples of coal1 oil1 etc41 for analysis and testing4 ,it is well known that1 under present methods of mining1 from #aj to #ge of any given deposit of coal is left underground as props and supports1 or as low-grade material1 or in overlying beds broken up through mining the lower bed first4 ,an average of #ej of the coal is thus wasted or rendered valueless1 as it cannot be removed subsequently because of the caving or falling in of the roofs of abandoned galleries and the breaking up of the adjoining overlying beds1 including coal1 floor1 and roof4 ,the investigations into waste in mining and the testing of the waste1 bone1 and slack coal in gas producers1 as briquettes1 etc41 have1 for their purpose1 the prevention of this form of waste by demonstrating that these materials1 now wasted1 may be used profitably1 by means of gas producers and engines1 for power purposes4 ,the third general line of investigation concerns the inspection and sampling of fuel delivered to the ,government under purchase contracts1 and the analyzing and testing of the samples collected1 to determine their heating value and the extent to which they may or may not comply with the specifications under which they are purchased4 ,the coal delivered at the public buildings in the ,district of ,columbia is sampled by special representatives of the ,technologic ,branch of the ,survey4 ,the taking of similar samples at public buildings and posts throughout the ,united ,states1 and the shipment of the samples in hermetically sealed cans or jars to the chemical laboratory at ,washington1 is for the most part looked after by special officers or employees at each place4 ,these purchases are made1 to an increasing extent1 under specifications which provide premiums for coal delivered in excess of standards1 and penalties for deliveries below standards fixed in the specifications4 ,the standard for bituminous coals is based mainly on the heat units1 ash1 and sulphur1 while that for anthracite coal is based mainly on the percentage of ash and the heat units4 ,in connection with all these lines of fuel testing1 certain research work1 both chemical and physical1 is carried on to determine the true composition and properties of the different varieties of coal1 the changes in the transformation from peat to lignite1 from lignite to bituminous coal1 and from bituminous to anthracite coal1 and the chemical and physical processes in combustion4 ,experiments are conducted concerning the destructive distillation of fuels2 the by-products of coking processes2 the spontaneous combustion of coal2 the storage of coal1 and the loss in value in various methods of storing2 and kindred questions1 such as the weathering of coal4 ,these experiments may yield valuable results through careful chemical research work supplemented by equally careful observations in the field4 ,inspection and ,mine ,sampling4--,in the ,geological ,survey ,building1 at ,washington1 coal purchased for ,government use on a guaranteed-analysis or heat-value basis1 is inspected and sampled4 ,some of the employees on this work are constantly at the mines taking samples1 or at public works inspecting coal for ,government use1 while others are stationed at ,washington to look after the deliveries of coal to the many public buildings1 and to collect and prepare samples taken from these deliveries for analysis1 as well as to prepare samples received from public works and buildings in other parts of the country4 ,illustration3 ,fig4 #aj4 ,,coal-,,sampling ,,room1 ,,geological ,,survey1 ,,washington1 ,d4,c4 ,the preparation of these samples is carried on in a room in the basement of the building1 where special machinery has been installed for this work4 ,fig4 #aj shows a plan of this room and the arrangement of the sampling and crushing machinery4 ,the crushing of the coal produces great quantities of objectionable dust1 and to prevent this dust from giving trouble outside the sampling room1 the wooden partitions on three sides of the room 7the fourth side being a masonry wall7 are completely covered on the outside with galvanized sheet iron4 ,the only openings to the room are two doors1 which are likewise covered with sheet iron1 and provided with broad flanges of the same material1 in order to seal effectually the openings when the doors are shut4 ,fresh air is drawn into the room by a fan1 through a pipe leading to the outer air4 ,a dust-collecting system which carries the coal dust and spent air from the room1 consists of an arrangement of #h-;in4 and #ab-;in4 pipes leading from hoods1 placed over the crushing machines1 to the main furnace stack of the building4 ,the draft in this stack draws all the dust from the crushers directly through the hoods to the main pipe1 where most of it is deposited4 ,the equipment of the sampling room consists of one motor-driven1 baby hammer crusher1 which has a capacity of about #a ton per hour and crushes to a fineness of -in4 mesh2 one adjustable chipmunk jaw crusher1 for #e- and #aj-lb4 samples2 one set of #d by #g-;in4 rolls1 crushing to #fj mesh1 for small samples2 one large bucking board1 and several different sizes of riffle samplers for reducing samples to small quantities4 ,the small crushers are belted to a shaft driven by a separate motor from that driving the baby crusher4 ,in conducting the inspection of departmental purchases of coal in ,washington1 the office is notified whenever a delivery of coal is to be made at one of the buildings1 and an inspector is sent1 who remains during the unloading of the coal4 ,he is provided with galvanized-iron buckets having lids and locks2 each bucket holds about #fj lb4 of coal4 ,in these buckets he puts small quantities of the coal taken from every portion of the delivery1 and when the delivery has been completed1 he locks the buckets and notifies the office to send a wagon for them4 ,the buckets are numbered consecutively1 and the inspector makes a record of these numbers1 the date1 point of delivery1 quality of coal delivered1 etc4 ,the buckets are also tagged to prevent error4 ,he then reports to the office in person1 or by telephone1 for assignment to another point in the city4 ,all the samples are delivered to the crushing room in the basement of the ,survey ,building1 to be prepared for analysis4#aa ,samples taken from coal delivered to points outside of ,washington are taken by representatives of the department for which the coal is being purchased1 according to instructions furnished them1 and1 from time to time1 the regular inspectors are sent to see that these instructions are being complied with4 ,these samples are crushed by hand1 reduced to about #b lb4 at the point where they are taken1 and sent to ,washington1 in proper air-tight containers1 by mail or express1 accompanied by appropriate descriptions4 ,each sample is entered in the sample record book when received1 and is given a serial number4 ,for each contract a card is provided giving information relative to the contract4 ,on this card is also entered the serial number of each sample of coal delivered under that contract4 ,after the samples are recorded1 they are sent to the crushing room1 where they are reduced to the proper bulk and fineness for analysis4 ,they are then sent1 in rubber-stoppered bottles1 accompanied by blank analysis report cards and card receipts1 one for each sample1 showing the serial numbers1 to the fuel laboratory for analysis4 ,the receipt card for each sample is signed and returned to the inspection office1 and when the analysis has been made1 the analysis report card showing the result is returned4 ,this result is entered at once on the contract card1 and when all analyses have been received1 covering the entire delivery of coal1 the average quality is calculated1 and the results are reported to the proper department4 ,the matter of supplying the ,pittsburg plant with fuel for test purposes is also carried on from the ,washington office4 ,preliminary to a series of investigations1 the kinds and amounts of coal required are decided on1 and the localities from which these coals are to be obtained are determined4 ,negotiations are then opened with the mine owners1 who1 in most cases1 generously donate the coal4 ,when the preliminaries have been arranged1 an inspector is sent to the mine to supervise the loading and shipment of the coal4 ,this inspector enters the mine and takes1 for chemical analysis1 small mine samples which are sent to the laboratory at ,pittsburg in metal cans by mail1 accompanied by proper identification cards4 ,the results of the analysis are furnished to the experts in charge at the testing plant1 for their information and guidance in the investigations for which the coal was shipped4 ,all samples for testing purposes are designated consecutively in the order of shipment1 8,pittsburg ,no4 #a10 8,pittsburg ,no4 #b10 etc4 ,a complete record of all shipments is kept on card forms at the ,pittsburg plant1 and a duplicate set of these is on file in the inspection office at ,washington4 ,analysis of ,fuels4--,the routine analyses of fuel used in the combustion tests at ,pittsburg1 and of the gases resulting from combustion or from explosions in the testing galleries1 or sampled in the mines1 are made in ,building ,no4 #ba4ab ,a small laboratory is also maintained on the second floor of the south end of ,building ,no4 #ac1 for analyses of gases resulting from combustion in the producer-gas plant1 and from explosions in ,galleries ,nos4 #a and #b1 etc4 ,from four to six chemists are continually employed in this laboratory 7in #h-;hour shifts71 during prolonged gas-producer tests1 and three chemists are also employed in analyzing gases relating to mine explosions4 ,in addition to these gas analyses1 there are also made in the main laboratory1 analyses and calorific tests of all coal samples collected by the ,geological ,survey in connection with its land-classification work on the coal lands of the ,western ,states4 ,routine analyses of mine1 car1 and furnace samples of fuels for testing1 before and after washing and briquetting1 before coking and the resultant coke1 and extraction analyses of binders for briquettes1 etc41 are also made in this laboratory4 ,the fuel-testing laboratory at ,washington is equipped with three ,mahler bomb calorimeters and the necessary balances and chemical equipment required in the proximate analysis of coal4 ,more than #fej deliveries of coal are sampled each month for tests1 representing #ej1jjj tons purchased per month1 besides daily deliveries1 on ship-board1 of #eej1jjj tons of coal for the ,panama ,railroad4 ,the data obtained by these tests furnish the basis for payment4 ,the tests cover deliveries of coal to the forty odd bureaus1 and to the ,district ,municipal buildings in ,washington2 to the arsenals at ,watertown1 ,mass41 ,frankford1 ,pa41 and ,rock ,island1 ,ill42 and to a number of navy yards1 through the ,bureau of ,yards and ,docks2 to military posts in various parts of the country2 for the ,quartermaster-,general's ,department2 to the ,reclamation ,service2 to ,indian ,agencies and ,soldiers' ,homes2 to several lighthouse districts2 and to the superintendents of the various public buildings throughout the ,united ,states1 through the ,treasury ,department2 etc4 ,during #aiji1 the average rate of reporting fuel samples was #edj per month1 requiring1 on an average1 six determinations per sample1 or about #c1bdj determinations per month4 ,fuel-,research ,laboratories4--,smaller laboratories1 occupying1 on the average1 three rooms each1 are located in ,building ,no4 #ba4 ,one is used for chemical investigations and calorific tests of petroleum collected from the various oil fields of the ,united ,states2 another is used for investigations relative to the extraction of coal and the rapidity of oxidization of coals by standard solutions of oxidizing agents2 and another is occupied with investigations into the destructive distillation of coal4 ,the researches under way show the wide variation in chemical composition and calorific value of the various crude oils1 indicate the possibility of the extraction of coal constituents by solvents1 and point to important results relative to the equilibrium of gases at high temperatures in furnaces and gas producers4 ,the investigations also bear directly on the coking processes1 especially the by-product process1 as showing the varying proportion of each of the volatile products derivable from types of coals occurring in the various coal fields of the ,united ,states1 the time and temperature at which these distillates are given off1 the variation in quality and quantity of the products1 according to the conditions of temperature1 and1 in addition1 explain the deterioration of coals in storage1 etc4 ,illustration3 ,fig4 #aa4 ,,plan ,,of ,,construction ,,details ,,of ,,metal ,,hood ,at the ,washington office1 microscopic investigations into the life history of coal1 lignite1 and peat are being conducted4 ,these investigations have already progressed far enough to admit of the identification of some of the botanical constituents of the older peats and the younger lignites1 and it is believed that the origin of the older lignites1 and even of some of the more recent bituminous coals1 may be developed through this examination4 ,in the chemical laboratories1 in ,building ,no4 #ba1 the hoods 7,figs4 #aa and #ab7 are of iron1 with a brick pan underneath4 ,they are supported on iron pipes1 as are most of the other fixtures in the laboratories in this building4 ,the hood proper is of japanned1 pressed-iron plate1 ,no4 #bb gauge1 the same material being used for the boxes1 slides1 and bottom surrounding the hood4 ,the sash is hung on red copper pulleys1 and the corners of the hood are reinforced with pressed1 japanned1 riveted plate to which the ventilating pipe is riveted4 ,illustration3 ,fig4 #ab4 ,,elevation ,,of ,,construction ,,details ,,of ,,metal ,,hood ,there is some variety in the cupboards and tables provided in the various laboratories1 but1 in general1 they follow the design shown in ,fig4 #ac4 ,the table tops1 #ab ft4 long1 are of clear maple in full-length pieces1 in4 thick and #b in4 wide1 laid on edge and drilled at #ah-;in4 intervals for bolts4 ,these pieces are glued and drawn together by the bolts1 the heads of which are countersunk4 ,the tops1 planed off1 sanded1 and rounded1 are supported on pipe legs and frames of #a by #a-;in4 galvanized-iron pipe with screw flanges fitting to the floor and top4 ,under the tops are drawers and above them re-agent shelves4 ,halfway between the table top and the floor is a wire shelf of a frame-work of ,no4 #b wire interlaced with ,no4 #ab weave of -in4 square mesh4 ,certain of the tables used in the laboratory are fitted with cupboards beneath and with drawers1 and1 in place of re-agent stands1 porcelain-lined sinks are sunk into them4 ,these tables follow1 in general style and construction1 the re-agent tables4 ,the tables used in connection with calorimeter determinations are illustrated in ,fig4 #ad4 ,the sinks provided throughout these laboratories are of standard porcelain enamel1 rolled rim1 #ah by #ac in41 with enameled back1 over a sink and drain board1 #bd in4 long on the left side1 though there are variations from this type in some instances4 ,the plumbing includes separate lines of pipe to each hood and table2 one each for cold water1 steam at from #e to #aj lb4 pressure1 compressed air1 natural gas1 and1 in some cases1 live steam at a pressure of #fj lb4 ,on each table is an exposed drainage system of #b-;in4 galvanized-iron pipe1 in the upper surface of which holes have been bored1 through which the various apparatus drain by means of flexible connections of glass or rubber4 ,these pipes and the sinks1 etc41 discharge into main drains1 hung to the ceiling of the floor beneath4 ,these drains are of wood1 asphaltum coated1 with an inside diameter ranging from #c to #f in41 and at the proper grades to secure free discharge4 ,these wooden drain-pipes are made in short lengths1 strengthened by a spiral wrapping of metal bands1 and are tested to a pressure of #dj lb4 per sq4 in4 ,angles are turned and branches connected in #d- and #f-;in4 square headers4 ,illustration3 ,fig4 #ac4 ,,plan ,,of ,,construction ,,details ,,of ,,reagent ,,tables ,,building #ba4 ,illustration3 ,fig4 #ad4 ,,construction ,,details ,,of ,,calorimeter ,,tables ,the entire building is ventilated by a force or blower fan in the basement1 and by an exhaust fan in the attic with sufficient capacity to insure complete renewal of air in each laboratory once in #bj min4 ,the blower fan is placed in the center of the building1 on the ground floor1 and is #ajj in4 in diameter4 ,its capacity is about #cj1jjj cu4 ft4 of air per min41 and it forces the air1 through a series of pipes1 into registers placed in each of the laboratories4 ,the exhaust fan1 in the center of the attic1 is run at #eej rev4 per min41 and has a capacity of #bb1fjj cu4 ft4 of air per min4 ,it draws the air from each of the rooms below1 as well as from the hoods1 through a main pipe1 #dh in4 in diameter4 ,steaming and ,combustion ,tests4--,the investigations included under the term1 fuel efficiency1 relate to the utilization of the various types of fuels found in the coal and oil fields1 and deal primarily with the combustion of such fuels in gas producers1 in the furnaces of steam boilers1 in locomotives1 etc41 and with the efficiency and utilization of petroleum1 kerosene1 gasoline1 etc41 in internal-combustion engines4 ,this work is under the general direction of ,mr4 ,r4 ,l4 ,fernald1 and is conducted principally in ,buildings ,nos4 #ac 7,plate ,,xvii7 and #ba4 ,for tests of combustion of fuels purchased by the ,government1 the equipment consists of two ,heine1 water-tube boilers1 each of #baj h4p41 set in ,building ,no4 #ac4 ,one of these boilers is equipped with a ,jones underfeed stoker1 and is baffled in the regular way4 ,at four points in the setting1 large pipes have been built into the brick wall1 to permit making observations on the temperature of the gas1 and to take samples of the gas for chemical analysis4 ,the other boiler is set with a plain hand-fired grate4 ,it is baffled to give an extra passage for the gases 7,fig4 #ae74 ,through the side of this boiler1 at the rear end1 the gases from the long combustion chamber 7,plate ,,xviii7 enter and take the same course as those from the hand-fired grate4 ,both the hand-fired grate and the long combustion chamber may be operated at the same time1 but it is expected that usually only one will be in operation4 ,a forced-draft fan has been installed at one side of the hand-fired boiler1 to provide air pressure when coal is being burned at high capacity4 ,this fan is also connected in such a way as to furnish air for the long combustion chamber when desired4 ,a more complete description of the boilers may be found in ,professional ,paper ,no4 #dh1 and ,bulletin ,no4 #cbe of the ,u4,s4 ,geological ,survey1 in which the water-measuring apparatus is also described4#ac ,on account of the distance from ,building ,no4 #ba to the main group of buildings1 it was considered inadvisable to attempt to furnish steam from ,building ,no4 #ac to ,building ,no4 #ba1 either for heating or power purposes4 ,in view1 moreover1 of the necessity of installing various types and sizes of house-heating boilers1 on account of tests to be made thereon in connection with these investigations1 it was decided to install these boilers in the lower floor of ,building ,no4 #ba1 where they could be utilized1 not only in making the necessary tests1 but in furnishing heat and steam for the building and the chemical laboratories therein4 ,illustration3 ,fig4 #ae4 ,,setting ,,for #baj-;,,horse ,,power1 ,,hand-,,fired ,,boilers ,in addition to the physical laboratory on the lower floor of ,building ,no4 #ba1 and the house-heating boiler plant with the necessary coal storage1 there are rooms devoted to the storage of heavy supplies1 samples of fuels and oils1 and miscellaneous commercial apparatus4 ,one room is occupied by the ventilating fan and one is used for the necessary crushers1 rolls1 sizing screens1 etc41 required in connection with the sampling of coal prior to analysis4 ,the ,quartermaster's ,department having expressed a wish that tests be made of the heating value and efficiency of the various fuels offered that ,department1 in connection with the heating of military posts throughout the country1 three house-heating boilers were procured which represent1 in a general way1 the types and sizes used in a medium-sized hospital or other similar building1 and in smaller residences 7,fig4 #b1 ,plate ,,xvi74 ,the larger apparatus is a horizontal return-tubular boiler1 #fj in4 in diameter1 #af ft4 long1 and having fifty-four #d-;in4 tubes4#ad ,in order to determine whether such a boiler may be operated under heating conditions without making smoke1 when burning various kinds of coal1 it has been installed in accordance with accepted ideas regarding the prevention of smoke4 ,a fire-brick arch extends over the entire grate surface and past the bridge wall4 ,a baffle wall has been built in the combustion chamber1 which compels the gases to pass downward and to divide through two openings before they reach the boiler shell4 ,provision has been made for the admission of air at the front of the furnace1 underneath the arch1 and at the rear end of the bridge wall1 thus furnishing air both above and below the fire4 ,it is not expected that all coals can be burned without smoke in this furnace1 but it is desirable to determine under what conditions some kinds of coals may be burned without objectionable smoke4#ae ,for sampling the gases in the smokebox of the horizontal return-tubular boiler1 a special flue-gas sampler was designed1 in order to obtain a composite sample of the gases escaping from the boiler4 ,the other heaters are two cast-iron house-heating boilers4 ,one can supply #djj sq4 ft4 of radiation and the other about #d1jjj sq4 ft4 ,they were installed primarily for the purpose of testing coals to determine their relative value when burned for heating purposes4 ,they are piped to a specially designed separator1 and from this to a pressure-reducing valve4 ,beyond this valve an orifice allows the steam to escape into the regular heating mains4 ,this arrangement makes it possible to maintain a practically constant load on the boilers4 ,illustration3 ,,plate ,,xviii4 ,fig4 #a4--,long ,combustion ,chamber4 ,fig4 #b4--;,gas ,sampling ,apparatus1 ,long ,combustion ,chamber4 ,there is a fourth boiler1 designed and built for testing purposes by the ,quartermaster's ,department4 ,this is a tubular boiler designed on the lines of a house-heating boiler1 but for use as a calorimeter to determine the relative heat value of different fuels reduced to the basis of a standard cord of oak wood4 ,a series of research tests on the processes of combustion is being conducted in ,building ,no4 #ac1 by ,mr4 ,henry ,kreisinger4 ,these tests are being made chiefly in a long combustion chamber 7,figs4 #af and #ag1 and ,figs4 #a and #b1 ,plate ,,xviii71 which is fed with coal from a ,murphy mechanical stoker1 and discharges the hot gases at the rear end of the combustion chamber1 into the hand-fired ,heine boiler4 ,the walls and roof of this chamber are double2 the inner wall is #i in4 thick1 of fire-brick2 the outer one is #h in4 thick1 and is faced with red pressed brick4 ,between the walls of the sides there is a #b-;in4 air space1 and between them on the roof a #a-;in4 layer of asbestos paste is placed4 ,the inner walls and roof have three special slip-joints1 to allow for expansion4 ,the floor is of concrete1 protected by a #a-;in4 layer of asbestos board1 which in turn is covered by a #c-;in4 layer of earth2 on top of this earth there is a #d-;in4 layer of fire-brick 7not shown in the drawings74 ,illustration3 ,fig4 #af4 ,,cross-,,sections ,,of ,,chamber ,,and ,,of ,,furnace1 ,,long ,,combustion ,,chamber ,inasmuch as one of the first problems to be attacked will be the determination of the length of travel and the time required to complete combustion in a flame in which the lines of stream flow are nearly parallel1 great care was taken to make the inner surfaces of the tunnel smooth1 and all corners and hollows are rounded out in the direction of travel of the gases4 ,provision is made1 by large peep-holes in the sides1 and by smaller sampling holes in the top1 for observing the fuel bed at several points and also the flame at #e-;ft4 intervals along the tunnel4 ,temperatures and gas samples are taken simultaneously at a number of points through these holes1 so as to determine1 if possible1 the progress of combustion 7,fig4 #a1 ,plate ,,xviii74 ,about twenty thermo-couples are embedded in the walls1 roof1 and floor1 some within #a in4 of the inside edge of the tunnel walls1 and some in the red pressed brick near the outer surface1 the object of which is to procure data on heat conduction through well-built brick walls#af 7,fig4 #b1 ,plate ,,xviii74 ,in order to minimize the leakage of air through the brickwork1 the furnace and tunnel are kept as nearly as possible at atmospheric pressure by the combined use of pressure and exhausting fans4 ,nevertheless1 the leakage is determined periodically as accurately as possible4 ,at first a number of tests were run to calibrate the apparatus as a whole1 all these preliminary tests being made on cheap1 carefully inspected1 uniform screenings from the same seam of the same mine near ,pittsburg4 ,later tests will be run with other coals of various volatile contents and various distillation properties4 ,it is anticipated that the progress of the tests may suggest changes in the construction or operation of this chamber4 ,it is especially contemplated that the section of the chamber may be narrowed down by laying sand in the bottom and fire-brick thereon2 also that baffle walls may be built into various portions of it1 and that cooling surfaces with baffling may be introduced4 ,in addition to variations in the tests1 due to changes in construction in the combustion chamber1 there will be variations in the fuels tested4 ,especial effort will be made to procure fuels ranging in volatile content from #ae to #bg and to #dj1 and those high in tar and heavy hydro-carbons4 ,it is also proposed to vary the conditions of testing by burning at high rates1 such as at #ae1 #bj1 and #cj lb4 per ft4 of grate surface1 and even higher4 ,records will be kept of the weight of coal fired and of each firing1 of the weight of ash1 etc42 samples of coal and of ash will be taken for chemical and physical analysis1 as well as samples of the gas1 and other essential data4 ,these records will be studied in detail4 ,illustration3 ,fig4 #ag4 ,,longitudinal ,,sections ,,of ,,long ,,combustion ,,chamber ,a series of heat-transmission tests undertaken two years ago1 is being continued on the ground floor of ,building ,no4 #ba1 on modified apparatus reconstructed in the light of the earlier experiments by ,mr4 ,w4 ,t4 ,ray4 ,the purpose of the tests on this apparatus has been to determine some of the laws controlling the rate of transmission of heat from a hot gas to a liquid and vice versa1 the two being on the opposite sides of a metal tube4 ,it appears that four factors determine the rate of heat impartation from the gas to any small area of the metal#ag3 ,footnote #ag3 ,the assumption is made that a metal tube free from scale will remain almost as cool as the water2 actual measurements with thermo-couples have indicated the correctness of this assumption in the majority of cases4 7#a74--,the temperature difference between the body of the gas and the metal2 7#b74--,the weight of the gas per cubic foot1 which is proportional to the number of molecules in any unit of volume2 7#c74--,the bodily velocity of the motion of the gas parallel to any small area under consideration2 and 7probably71 7#d74--,the specific heat of the gas at constant pressure4 ,the apparatus consists of an electric resistance furnace containing coils of nickel wire1 a small 7interchangeable7 multi-tubular boiler1 and a steam-jet apparatus for reducing the air pressure at the exit end1 so as to cause a flow of air through the boiler4 ,a surface condenser was attached to the boiler's steam outlet1 the condensed steam being weighed as a check on the feed-water measurements4 ,a number of thermometers and thermo-couples were used to obtain atmospheric-air temperature1 temperatures of the air entering and leaving the boilers1 and feed-water temperature4 ,the apparatus is now being reconstructed with appliances for measuring the quantity of air entering the furnace1 and an automatic electric-furnace temperature regulator4 ,illustration3 ,,plate ,,xix4 ,fig4 #a4--;,gas ,producer1 ,economizer1 and ,wet ,scrubber4 ,fig4 #b4--,producer ,gas3 ,dry ,scrubber and ,gas ,holder4 ,three sizes of boiler have been tested thus far1 the dimensions being as given in ,table #d4 ,each of the three boilers was tested at several temperatures of entering air1 up to #a1ejj ,fahr41 about ten tests being made at each temperature4 ,it is also the intention to run1 on these three boilers1 about eight tests at temperatures of #a1hjj1 #b1ajj and #b1djj ,fahr41 respectively4 ,a bulletin on the work already done1 together with much incidental matter1 is in course of preparation4#ah ,,table #d4--;,dimensions of ,boilers ,nos4 #a1 #b1 and #c4 ---------------------------------------- -------------------- ,items4 ,boiler ,boiler ,boiler ,no4 #a4 ,no4 #b4 ,no4 #c4 ---------------------------------------- -------------------- ,distance1 outside to outside of boiler heads1 in inches #h4bh #h4bh #af4abe ,actual outside diameter of flues1 #j4beb #j4cac #j4beb in inches ,actual inside diameter of flues1 #j4age #j4bcj #j4age in inches ,number of flues 7tubes7 #aj #aj #aj ---------------------------------------- -------------------- ,the work on the first three boilers is only a beginning2 preparations are being made to test eight more multi-tubular boilers of various lengths and tube diameters1 under similar conditions4 ,because of the experience already obtained1 it will be necessary to make only eight tests at each initial air temperature4 ,when the work on multi-tubular boilers is completed1 water-tube boilers will be taken up1 for which a fairly complete outline has been prepared4 ,this second or water-tube portion of the investigation is really of the greater scientific and commercial interest1 but the multi-tubular boilers were investigated first because the mathematical treatment is much simpler4 ,producer-,gas ,tests4--,the producer-gas plant at the ,pittsburg testing station is in charge of ,mr4 ,carl ,d4 ,smith1 and has been installed for the purpose of testing low-grade fuel1 bone coal1 roof coal1 mine refuse1 and such material as is usually considered of little value1 or even worthless for power purposes4 ,the gas engine1 gas producer1 economizer1 wet scrubber 7,fig4 #a1 ,plate ,,xix71 and accessories1 are in ,building ,no4 #ac1 and the dry scrubber1 gas-holder1 and water-cooling apparatus are immediately outside that building 7,fig4 #b1 ,plate ,,xix74 ,at present immense quantities of fuel are left at the mines1 in the form of culm and slack1 which1 in quality1 are much below the average output4 ,such fuel is considered of little or no value1 chiefly because there is no apparatus in general use which can burn it to good advantage4 ,the heat value of this fuel is often from #ej to #ge of that of the fuel marketed1 and if not utilized1 represents an immense waste of natural resources4 ,large quantities of low-grade fuel are also left in the mines1 simply because present conditions do not warrant its extraction1 and it is left in such a way that it will be very difficult1 if not practically impossible1 for future generations to take out such fuel when it will be at a premium4 ,again1 there are large deposits of low-grade coal in regions far remote from the sources of the present fuel supply1 but where its successful and economic utilization would be a boon to the community and a material advantage to the country at large4 ,the great importance of the successful utilization of low-grade fuel is obvious4 ,until within very recent years little had been accomplished along these lines1 and there was little hope of ever being able to use these fuels successfully4 ,the development of the gas producer for the utilization of ordinary fuels1#ai however1 indicates that the successful utilization of practically all low-grade fuel is well within the range of possibility4 ,it is notable that1 although all producer-gas tests at the ,government testing stations1 at ,st4 ,louis and ,norfolk1 were made in a type of producer#bj designed primarily for a good grade of anthracite coal1 the fuels tested included a wide range of bituminous coals and lignites1 and even peat and bone coal1 and that1 in nearly every test1 little serious difficulty was encountered in maintaining satisfactory operating conditions4#ba ,it is interesting to note that in one test1 a bone coal containing more than #de of ash was easily handled in the producer1 and that practically full load was maintained for the regulation test period of #ej hours4#bb ,it is not expected that all the fuels tested will prove to be of immediate commercial value1 but it is hoped that much light will be thrown on this important problem4 ,illustration3 ,,plate ,,xx4 ,fig4 #a4--;,charging ,floor of ,gas ,producer4 ,fig4 #b4--;,european and ,american ,briquettes4 ,the equipment for this work consists of a single gas generator1 rated at #aej h4p41 and a three-cylinder1 vertical gas engine of the same capacity4 ,the producer is a ,loomis-,pettibone1 down-draft1 made by the ,power and ,mining ,machinery ,company1 of ,cudahy1 ,wis41 and is known as its 8,type ,c0 plant4 ,the gas generator consists of a cylindrical shell1 #f ft4 in diameter1 carefully lined with fire-brick1 and having an internal diameter of approximately #d ft4 ,near the bottom of the generator there is a fire-brick grate1 on which the fuel bed rests4 ,the fuel is charged at the top of the producer through a door 7,fig4 #a1 ,plate ,,xx71 which may be left open a considerable time without affecting the operation of the producer1 thus enabling the operator to watch and control the fuel bed with little inconvenience4 ,as the gas is generated1 it passes downward through the hot fuel bed and through the fire-brick grate4 ,this down-draft feature 8fixes10 or makes into permanent gases1 the tarry vapors which are distilled from bituminous coal when it is first charged into the producer4 ,a motor-driven exhauster with a capacity of #cge cu4 ft4 per min41 draws the hot gas from the base of the producer through an economizer1 where the sensible heat of the gas is used to pre-heat the air and to form the water vapor necessary for the operation of the producer4 ,the pre-heated air and vapor leave the economizer and enter the producer through a passageway near the top and above the fuel bed4 ,from the economizer the gas is drawn through a wet scrubber where it undergoes a further cooling and is cleansed of dirt and dust4 ,after passing the wet scrubber1 the gas1 under a light pressure1 is forced1 by the exhauster1 through a dry scrubber to a gas-holder with a capacity of about #a1jjj cu4 ft4 ,all the fuel used is carefully weighed on scales which are checked from time to time by standard weights2 and1 as the fuel is charged into the producer1 a sample is taken for chemical analysis and for the determination of its calorific power4 ,the water required for the generation of the vapor is supplied from a small tank carefully graduated to pounds2 this observation is made and recorded every hour4 ,all the water used in the wet scrubber is measured by passing it through a piston-type water meter1 which is calibrated from time to time to insure a fair degree of accuracy in the measurement4 ,provision is made for observing the pressure and temperature of the gas at various points2 these are observed and recorded every hour4 ,from the holder the gas passes through a large meter to the vertical three-cylinder ,westinghouse engine1 which is connected by a belt to a #age-kw41 direct-current generator4 ,the load on the generator is measured by carefully calibrated switch-board instruments1 and is regulated by a specially constructed water rheostat which stands in front of the building4 ,careful notes are kept of the engine operation2 the gas consumption and the load on the engine are observed and recorded every #bj min42 the quantity of jacket water used on the gas engine1 and also its temperature entering and leaving the engine jackets1 are recorded every hour4 ,indicator cards are taken every #b hours4 ,the work is continuous1 and each day is divided into three shifts of #h hours each2 the length of a test1 however1 is determined very largely by the character and behavior of the fuel used4 ,a preliminary study of the relative efficiency of the coals found in different portions of the ,united ,states1 as producers of illuminating gas1 has been nearly completed under the direction of ,mr4 ,alfred ,h4 ,white1 and a bulletin setting forth the results is in press4#bc ,tests of ,liquid ,fuels4--,tests of liquid fuels in internal-combustion engines1 in charge of ,mr4 ,r4 ,m4 ,strong1 are conducted in the engine-room of ,building ,no4 #ac4 ,the various liquid hydro-carbon fuels used in internal-combustion engines for producing power1 range from the light refined oils1 such as naphtha1 to the crude petroleums1 and have a correspondingly wide variation of physical and chemical properties4 ,the most satisfactory of the liquid fuels for use in internal-combustion engines1 are alcohol and the light refined hydro-carbon oils1 such as gasoline4 ,these fuels1 however1 are the most expensive in commercial use1 even when consumed with the highest practical efficiency1 which1 it is thought1 has already been attained1 as far as present types of engines are concerned4 ,at present little is known as to how far many of the very cheap distillates and crude petroleums can be used as fuel for internal-combustion engines4 ,it is difficult to use them at all1 regardless of efficiency4 ,gasoline is comparatively constant in quality1 and can be used with equal efficiency in any gasoline engine of the better grade4 ,there are many makes of high-grade gasoline engines1 tests on any of which may be taken as representative of the performance and action of gasoline in an internal-combustion engine1 if the conditions under which the tests were made are clearly stated and are similar4 ,kerosene varies widely in quality1 and requires special devices for its use1 but is a little cheaper than gasoline4 ,it is possible that the kerosene engine may be developed so as to permit it to take the place of the smaller stationary and marine gasoline engines4 ,this would mean considerable saving in fuel cost to the small power user1 who now finds the liquid-fuel internal-combustion engine of commercial advantage4 ,a number of engines at present on the market use kerosene2 some use only the lighter grades and are at best comparatively less efficient than gasoline engines4 ,all these engines have to be adjusted to the grade of oil to be used in order to get the best results4 ,kerosene engines are of two general types3 the external-vaporizer type1 in which the fuel is vaporized and mixed with air before or as it is taken into the cylinder2 and the internal-vaporizer type1 in which the liquid fuel is forced into the cylinder and vaporized by contact with the hot gases or heated walls of a combustion chamber at the head of the cylinder4 ,a number of special devices for vaporizing kerosene and the lighter distillates have been tried and used with some success4 ,heat is necessary to vaporize the kerosene as quickly as it is required1 and the degree of heat must be held between the temperature of vaporization and that at which the oil will be carbonized4 ,the vapor must also be thoroughly and uniformly mixed with air in order to obtain complete combustion4 ,as yet1 no reliable data on these limiting temperatures for kerosene and similar oils have been obtained4 ,no investigation has ever been made of possible methods for preventing the oils from carbonizing at the higher temperatures1 and the properties of explosive mixtures of oil vapors and air have not been studied4 ,this field of engineering laboratory research is of vital importance to the solution of the kerosene-engine problem4 ,distillates or fuel oils and the crude oils are much the cheapest of the liquid fuels1 and if used efficiently in internal-combustion engines would be by far the cheapest fuels available in many large districts4 ,several engine builders are developing kerosene vaporizers1 which are built as a part of the engine1 or are adapted to each different engine1 as required to obtain the best results4 ,most of these vaporizers use the heat and the exhaust gases to vaporize the fuel1 but they differ greatly in construction2 some are of the retort type1 and others are of the float-feed carburetter type4 ,to what extent the lower-grade fuel oils can be used with these vaporizers is yet to be determined4 ,there are only a few successful oil engines on the ,american market4 ,the most prominent of these represent specific applications of the principal methods of internal vaporization1 and all except one are of the hot-bulb ignition type4 ,it will probably be found that no one of the #d-stroke cycle1 or #b-stroke cycle1 engines is best for all grades of oil1 but rather that each is best for some one grade4 ,the ,diesel engine is in a class by itself1 its cycle and method of control being somewhat different from the others4 ,an investigation of the comparative adaptability of gasoline and alcohol to use in internal-combustion engines1 consisting of more than #b1jjj tests1 was made at the temporary fuel-testing plant of the ,geological ,survey1 at ,norfolk1 ,va41 in #aijg4 ,a detailed report of these tests is in preparation4#bd ,a similar investigation of the comparative adaptability of kerosenes has been commenced1 with a view to obtaining data on their economical use1 leading up to the investigation of the comparative fuel values of the cheaper distillates and crude petroleum1 as before discussed4 ,washing and ,coking ,tests4--,the investigations relating to the preparation of low-grade coals1 such as those high in ash or sulphur1 by processes that will give them a higher market value or increase their efficiency in use1 are in charge of ,mr4 ,a4 ,w4 ,belden4 ,they include the washing and coking tests of coals1 and the briquetting of slack and low-grade coal and culm-bank refuse so as to adapt these fuels for combustion in furnaces1 etc4 ,this work has been conducted in the washery and coking plant temporarily located at ,denver1 ,colo41 and in ,building ,no4 #cb at the ,pittsburg testing station1 where briquetting is in progress4 ,the details of these tests are set forth in the various bulletins issued by the ,geological ,survey4#be ,the washing tests are carried out in the following manner3 ,as the raw coal is received at the plant1 it is shoveled from the railroad cars to the hopper scale1 and weighed4 ,it then passes through the tooth-roll crusher1 where the lumps are broken down to a maximum size of #b in4 ,an apron conveyor delivers the coal to an elevator which raises it to one of the storage bins4 ,as the coal is being elevated1 an average sample representing the whole shipment is taken4 ,an analysis is made of this sample of raw coal and float-and-sink tests are run to determine the size to which it is necessary to crush before washing1 and the percentage of refuse with the best separation4 ,from the data thus obtained1 the washing machines are adjusted so that the washing test is made with full knowledge of the separations possible under varying percentages of refuse4 ,the raw coal is drawn from the bin and delivered to a corrugated-roll disintegrator1 where it is crushed to the size found most suitable1 and is then delivered by the raw-coal elevator to another storage bin4 ,the arrangement of the plant is such that the coal may be first washed on a ,stewart jig1 and the refuse then delivered to and re-washed on a special jig1 or the refuse may be re-crushed and then re-washed4 ,when the coal is to be washed1 it drops to the sluice box1 where it is mixed with the water and sluiced to the jigs4 ,in drawing off the washed coal1 or when the uncrushed raw coal is to be drawn from a bin and crushed for the washing tests1 however1 a gate just below the coal-flow regulating gate is thrown in1 and the coal falls into a central hopper instead of into the sluice box4 ,ordinarily1 this gate forms one side of the vertical chute4 ,the coal in this central hopper is carried by a chute to the apron conveyor1 and thence to the roll disintegrator1 or1 in case it is washed coal1 to a swing-hammer crusher4 ,it will be noted that coal1 in this manner1 can be drawn from a bin at the same time that coal is being taken from another bin1 and sluiced to the jigs for washing1 the two operations not interfering in the least4 ,the washed coal1 after being crushed and elevated to the top of the building1 is conveyed by a chute to the coke-oven larry1 and is weighed on the track scale1 after which it is charged to the oven4 ,the refuse is sampled and weighed as it is wheeled to the dump pile1 and from this sample the analysis is made and a float-and-sink test run to determine the 8loss of good coal0 in the refuse and to show the efficiency of the washing test4 ,the coking tests have been conducted in a battery of two beehive ovens1 one #g ft4 high and #ab ft4 in diameter1 the other1 #f ft4 high and #ab ft4 in diameter4 ,a standard larry with a capacity of #h tons1 and the necessary scales for weighing accurately the coal charged and coke produced1 complete the equipment4 ,the coal is usually run through a roll crusher which breaks it to about -in4 size1 or through a ,pennsylvania hammer crusher4 ,the fineness of the coals put through the hammer crusher varies somewhat1 but the average1 taken from a large number of samples1 is as follows3 ,through -in4 mesh1 #ajj2 over #aj-mesh1 #ca4dc2 over #bj-mesh1 #bd4bi2 over #dj-mesh1 #bb4hf2 over #fj-mesh1 #aj per cent4 ,the results of the coking tests are set forth in detail in the various publications issued on this subject4#bf ,tests of coke produced in the illuminating-gas investigations before referred to1 and a study of commercial coking and by-product plants1 are included in these investigations4 ,briquetting ,investigations4--,these investigations are in charge of ,mr4 ,c4 ,l4 ,wright1 and are conducted in ,building ,no4 #cb1 which is of fire-proof construction1 having a steel-skeleton frame work1 reinforced-concrete floors1 and #b-;in4 cement curtain walls1 plastered on expanded-metal laths4 ,in this building two briquetting machines are installed1 one an ,english machine of the ,johnson type1 and the other a ,german lignite machine of very powerful construction4 ,the investigations include the possibility of making satisfactory commercial fuels from lignite or low-grade coals which do not stand shipment well1 the benefiting of culm or slack coals which are wasted or sold at unremunerative prices1 and the possibility of improving the efficiency of good coals4 ,some of the various forms of commercial briquettes1 ,american and foreign1 are shown in ,fig4 #b1 ,plate ,,xx4 ,after undergoing chemical analysis1 the coal is elevated and fed to a storage bin1 whence it is drawn through a chute to a hopper on the weighing scales4 ,there it is mixed with varying percentages of different kinds of binding material1 and the tests are conducted so as to ascertain the most suitable binder for each kind of fuel1 which will produce the most durable and weather-proof briquette at least cost1 and the minimum quantity necessary to produce a good1 firm briquette4 ,after weighing1 the materials to be tested are run through the necessary grinding and pulverizing machines and are fed into the briquetting machines1 whence the manufactured briquettes are delivered for loading or storage4 ,the materials to be used in the ,german machine are also dried and cooled again4 ,illustration3 ,,plate ,,xxi4 ,fig4 #a4--;,hand ,briquetting ,press4 ,fig4 #b4--;,coal ,briquetting ,machine4 ,the briquettes made at this plant are then subjected to physical tests in order to determine their weathering qualities and their resistance to abrasion2 extraction tests and chemical analyses are also made4 ,meanwhile other briquettes from the same lots are subjected to combustion tests for comparison with the same coal not briquetted4 ,these tests are made in stationary boilers1 in house-heating boilers1 on locomotives1 naval vessels1 etc41 and the results1 both of the processes of manufacture1 and of the tests1 are published in various bulletins issued by the ,geological ,survey4#bg ,the equipment includes storage bins for the raw coal1 scales for weighing1 machines for crushing or cracking the pitch1 grinders1 crushers1 and disintegrators for reducing the coal to the desired fineness1 heating and mixing apparatus1 presses and moulds for forming the briquettes1 a ,schulz drier1 and a cooling apparatus4 ,there is a small experimental hand-briquetting press 7,fig4 #a1 ,plate ,,xxi7 for making preliminary tests of the briquetting qualities of the various coals and lignites4 ,with this it is easily possible to vary the pressure1 heat1 percentage and kind of binder1 so as to determine the best briquetting conditions for each fuel before subjecting it to large-scale commercial tests in the big briquetting machines4 ,this hand press will exert pressures up to #ej tons or #ajj1jjj lb4 per sq4 in41 on a plunger #c in4 in diameter4 ,this plunger enters a mould1 which can be heated by a steam jacket supplied with ordinary saturated steam at a pressure of #abe lb41 and compresses the fuel into a briquette1 #h in4 long1 under the conditions of temperature and pressure desired4 ,the ,johnson briquetting machine1 which requires #be h4p4 for its operation1 exerts a pressure of about #b1ejj lb4 per sq4 in41 and makes briquettes of rectangular form1 #f by #d by #b in41 and having an average weight of about #c lb4 ,the capacity of the machine 7,fig4 #b1 ,plate ,,xxi7 is about #c4h tons of briquettes per #h-;hour day4 ,under the hopper on the scales for the raw material is a square wooden reciprocal plunger which pushes the fuel into a hole in the floor at a uniform rate4 ,the pitch is added as uniformly as possible by hand1 as the coal passes this hole4 ,under this hole a horizontal screw conveyor carries the fuel and pitch to the disintegrator1 in front of which1 in the feeding chute1 there is a powerful magnet for picking out any pieces of iron which might enter the machine and cause trouble4 ,the ground mixture is elevated from the disintegrator to a point above the top of the upper mixer of the machine4 ,at the base of this cylinder1 steam can be admitted by several openings to heat the material to any desired temperature1 usually from #ahj to #bje ,fahr4 ,there1 a plunger1 making #ag strokes per min41 compresses two briquettes at each stroke4 ,the ,german lignite-briquetting machine 7,figs4 #ah and #ai7 was made by the ,maschinenfabrik ,buckau ,actien-,gesellschaft1 ,magdeburg1 ,germany4 ,lignite from the storage room on the third floor of the building is fed into one end of a ,schulz tubular drier 7,fig4 #a1 ,plate ,,xxii71 which is similar to a multi-tubular boiler set at a slight angle from the horizontal1 and slowly revolved by worm and wheel gearing1 the lignite passing through the tubes and the steam being within the boiler4 ,from this drier the lignite passes through a sorting sieve and crushing rolls to a cooling apparatus1 which consists of four horizontal circular plates1 about #ac ft4 in diameter1 over which the dried material is moved by rakes4 ,after cooling1 the material is carried by a long1 worm conveyor to a large hopper over the briquette press1 and by a feeding box to the press 7,fig4 #b1 ,plate ,,xxii74 ,the press1 which is of the open-mould type1 consists of a ram and die plates1 the latter being set so as to make a tube which gradually tapers toward the delivery end of the machine4 ,the briquettes have a cross-section similar to an ellipse with the ends slightly cut off2 they are about #a in4 thick and average about #a lb4 in weight 7,fig4 #b1 ,plate ,,xx74 ,the press is operated by a direct connection with a steam engine of #aej h4p41 the base of which is continuous with that of the press4 ,the exhaust steam from the engine is used to heat the driver4 ,the plunger makes from #hj to #ajj strokes per min41 the pressure exerted ranging from #ad1jjj to #bh1jjj lb4 per sq4 in41 the capacity of the machine being #a briquette per stroke1 or from #b to #c tons of completed briquettes per hour4 ,it is expected that no binder will be needed for practically all the brown lignite briquetted by this machine1 thus reducing the cost as compared with the briquetting of coals1 which require from #e to #g of water-gas1 pitch binder costing more than #ej cents per ton of manufactured briquettes4 ,illustration3 ,fig4 #ah4 ,,longitudinal-,,section ,,of ,,lignite-,,briquetting ,,plant ,illustration3 ,fig4 #ai4 ,,cross-,,section ,,of ,,lignite-,,briquetting ,,plant ,peat ,investigations4--,investigations into the distribution1 production1 origin1 nature1 and uses of peat are being conducted by ,mr4 ,c4 ,a4 ,davis1 and include co-operative arrangements with ,state ,geological ,surveys and the ,geologic ,branch of the ,u4,s4 ,geological ,survey4 ,these organizations conduct surveys which include the mapping of the peat deposits in the field1 the determination of their extent and limitations1 the sampling of peat from various depths1 and the transmittal of samples to the ,pittsburg laboratories for analysis and test4#bh ,this work is co-ordinated in such a manner as to result in uniform methods of procedure in studying the peat deposits of the ,united ,states4 ,the samples of peat are subjected to microscopic examination1 in order to determine their origin and age1 and to chemical and physical tests at the laboratories in ,pittsburg1 so as to ascertain the chemical composition and calorific value1 the resistance to compressive strains1 the ash and moisture content1 drying properties1 resistance to abrasion1 etc4 ,occasionally1 large quantities of peat are disintegrated and machined1 and portions1 after drying for different periods1 are subjected to combustion tests in steam boilers and to tests in the gas producer1 to ascertain their efficiency as power producers4 ,results4--,the full value of such investigations as have been described in the preceding pages cannot be realized for many years2 but1 even within the four years during which this work has been under way1 certain investigations have led to important results1 some of which may be briefly mentioned3 ,the chemical and calorific determinations of coals purchased for the use of the ,government have resulted in the delivery of a better grade of fuel without corresponding increase in cost1 and1 consequently1 in saving to the ,government4 ,under this system1 of purchasing its coal under specifications and testing1 the ,government is getting more nearly what it pays for and is paying for what it gets4 ,these investigations1 by suggesting changes in equipment and methods1 are also indicating the practicability of the purchase of cheaper fuels1 such as bituminous coal and the smaller sizes of pea1 buckwheat1 etc41 instead of the more expensive sizes of anthracite1 with a corresponding saving in cost4 ,the ,government's fuel bill now aggregates about #aj1jjj1jjj yearly4 ,illustration3 ,,plate ,,xxii4 ,fig4 #a4--;,dryer for ,lignite ,briquetting ,press4 ,fig4 #b4--,lignite ,briquetting ,machine4 ,the making and assembling of chemical analyses and calorific determinations 7checked by other tests7 of carefully selected samples of coals from nearly #a1jjj different localities1 in the different coal fields of the ,united ,states1 with the additions1 from time to time1 of samples representing parts of coal fields or newly opened beds of coal in the same field1 furnish invaluable sources of accurate information1 not only for use of the ,government1 but also for the general public4 ,of the above-mentioned localities1 #eja were in the public-land ,states and #dbg in the ,central1 ,eastern1 and ,southern ,states4 ,the chemical analyses of the coals found throughout the ,united ,states have been made with such uniformity of method1 both as to collection of samples and analytical procedure1 as to yield results strictly comparable for coals from all parts of the country1 and furnish complete information1 as a basis for future purchases and use by the ,government and by the general public1 of all types of ,american coals4 ,other researches have resulted in the acquirement of valuable information regarding the distribution of temperature in the fuel bed of gas producers and furnaces1 showing a range of from #djj to #a1cjj cent41 and have thus furnished data indicating specific difficulties to be overcome in gas-producer improvements for greater fuel efficiency4 ,the recent studies of the volatile matter in coal1 and its relation to the operation of coke ovens and other forms of combustion1 have demonstrated that as much as one-third of this matter is inert and non-combustible1 a fact which may have a direct bearing on smoke prevention by explaining its cause and indicating means for its abatement4 ,experiments in the storage of coal have proven that oxygen is absorbed during exposure to air1 thereby causing1 in some cases1 a deterioration in heating value1 and indicating that1 for certain coals1 in case they are to be stored a long time for naval and other purposes1 storage under water is advisable4 ,the tests of different coals under steam boilers have shown the possibility of increasing the general efficiency of hand-fired steam boilers from #aj to #ae over ordinary results4 ,if this saving could be made in the great number of hand-fired boilers now being operated in all parts of the ,united ,states1 it would result in large saving in the fuel bill of the country4 ,experiments which have been made with residence-heating boilers justify the belief that it will be possible to perfect such types of boilers as may economically give a smokeless operation4 ,the tests under steam boilers furnish specific information as to the most efficient method of utilizing each of a number of different types of coal in ,government buildings and power plants in different parts of the country4 ,the tests in the gas producer have shown that many fuels of such low grade as to be practically valueless for steam-furnace purposes1 including slack coal1 bone coal1 and lignite1 may be economically converted into producer gas1 and may thus generate sufficient power to render them of high commercial value4 ,practically every shipment out of several hundred tested in the gas producers1 including coals as high in ash content as #de1 and lignites and peats high in moisture1 has been successfully converted into producer gas which has been used in operating gas engines4 ,it has been estimated that on an average there was developed from each coal tested in the gas-producer plant two and one-half times the power developed when used in the ordinary steam-boiler plant1 and that such relative efficiencies will probably hold good for the average plant of moderate power capacity1 though this ratio may be greatly reduced in large steam plants of the most modern type4 ,it was found that the low-grade lignites of ,north ,dakota developed as much power1 when converted into producer gas1 as did the best ,west ,virginia bituminous coals when utilized under the steam boiler2 and1 in this way1 lignite beds underlying from #bj1jjj1jjj to #cj1jjj1jjj acres of public lands1 supposed to have little or no commercial value1 are shown to have a large value for power development4 ,the tests made with reference to the manufacture and combustion of briquetted coal have demonstrated conclusively that by this means many low-grade bituminous coals and lignites may have their commercial value increased to an extent which more than covers the increased cost of making2 and these tests have also shown that bituminous coals of the higher grades may be burned in locomotives with greatly increased efficiency and capacity and with less smoke than the same coal not briquetted4 ,these tests have shown that1 with the same fuel consumption of briquettes as of raw coal1 the same locomotive can very materially increase its hauling capacity and thus reduce the cost of transportation4 ,the investigations into smoke abatement have indicated clearly that each type of coal may be burned practically without smoke in some type of furnace or with some arrangement of mechanical stoker1 draft1 etc4 ,the elimination of smoke means more complete combustion of the fuel1 and consequently less waste and higher efficiency4 ,the investigations into the waste of coal in mining have shown the enormous extent of this waste1 aggregating probably from #cjj1jjj1jjj to #djj1jjj1jjj tons yearly1 of which at least one-half might be saved4 ,it is being demonstrated that the low-grade coals1 high in sulphur and ash1 now left underground1 can be used economically in the gas producer for power and light1 and1 therefore1 should be mined at the same time that the high-grade coal is being removed4 ,moreover1 attention is now being called to the practicability of a further large reduction of waste through more efficient mining methods4 ,the washing tests have demonstrated the fact that many coals1 too high in ash and sulphur for economic use under the steam boiler or for coking1 may be rendered of commercial value by proper treatment in the washery4 ,the coking tests have also demonstrated that1 by proper methods of preparation for and manipulation in the beehive oven1 many coals which were not supposed to be of economic value for coking purposes1 may be rendered so by prior washing and proper treatment4 ,of more than #ajj coals tested during #aijf from the ,mississippi ,valley and the ,eastern ,states1 most of which coals were regarded as non-coking1 all except #f were found1 by careful manipulation1 to make fairly good coke for foundry and other metallurgical purposes4 ,of #eb coals from the ,rocky ,mountain region1 all but #c produced good coke under proper treatment1 though a number of these had been considered non-coking coals4 ,investigations into the relative efficiency of gasoline and denatured alcohol as power producers1 undertaken in connection with work for the ,navy ,department1 have demonstrated that with proper manipulation of the carburetters1 igniters1 degree of compression1 etc41 denatured alcohol has the same power-producing value1 gallon for gallon1 as gasoline4 ,this is a most interesting development1 in view of the fact that the heat value of a gallon of alcohol is only a little more than #j4f that of a gallon of gasoline4 ,to secure these results1 compressions of from #aej to #ahj lb4 per sq4 in4 were used1 these pressures involving an increase in weight of engine4 ,although the engine especially designed for alcohol will be heavier than a gasoline engine of the same size1 it will have a sufficiently greater power capacity so that the weight per horse-power need not be greater4 ,several hundred tons of peat have been tested to determine methods of drying1 compressing into briquettes1 and utilization for power production in the gas producer4 ,in connection with these peat investigations1 a reconnoissance survey has been made of the peat deposits of the ,atlantic ,coast4 ,samples have been obtained by boring to different depths in many widely distributed peat-bogs1 and these samples have been analyzed and tested in order to determine their origin1 nature1 and fuel value4 ,the extent and number of tests from which these results have been derived will be appreciated from the fact that1 in three years1 nearly #ae1jjj tests were made1 in each of which large quantities of fuel were consumed4 ,these tests involved nearly #a1bej1jjj physical observations and #fg1jhj chemical determinations1 made with a view to analyze the results of the tests and to indicate any necessary changes in the methods as they progressed4 ,for coking1 cupola1 and washing1 #eif tests1 of which nearly #cjj involved the use of nearly #a1jjj tons of coal1 have been made at ,denver4 ,for briquetting1 #cab tests have been made4 ,briquettes have been used in combustion tests in which #bej tons of briquetted coal were consumed in battleship tests1 #baj tons in torpedo-boat tests1 #cbj tons in locomotive tests on three railway systems1 and #gj tons were consumed under stationary steam boilers4 ,of producer gas tests1 #age have been made1 of which #g were long-time runs of a week or more in duration1 consuming in all #aje tons of coal4 ,there have been #cjj house-heating boiler tests and #ege steam-boiler tests2 also1 #hc railway-locomotive and #bc naval-vessel tests have been made on run-of-mine coal in comparison with briquetted coal2 also1 #abe tests have been made in connection with heat-transmission experiments1 and #b1bed gasoline- and alcohol-engine tests4 ,nearly #aj1jjj samples of coal were taken for analysis1 of which #c1jjj were from public-land ,states4 ,nearly #e1jjj inspection samples1 of coal purchased by the ,government for its use1 have been taken and tested4 ,the results of the tests made in the course of these investigations1 as summarized1 have been published in twelve separate ,bulletins1 three of which1 ,nos4 #bfa1 #bij1 and #ccb1 set forth in detail the operations of the fuel-testing plant for #aijd1 #aije1 and #aijf4 ,professional ,paper ,no4 #dh1 in three volumes1 describes in greater detail each stage of the operations for #aijd and #aije4 ,separate ,bulletins1 descriptive of the methods and results of the work in detail1 have been published1 as follows3 ,no4 #cbc1 ,experimental work conducted in the chemical laboratory2 ,no4 #cbe1 ,a study of four hundred steaming tests2 ,no4 #ccd1 ,burning of coal without smoke in boiler plants2 ,no4 #ccf1 ,washing and coking tests of coal1 and cupola tests of coke2 ,no4 #cci1 ,purchase of coal under specifications on basis of heating value2 ,no4 #cdc1 ,binders for coal briquettes2 ,no4 #cfb1 ,mine sampling and chemical analyses of coals in #aijg2 ,no4 #cfc1 ,comparative tests of run-of-mine and briquetted coal on locomotives1 including torpedo-boat tests1 and some foreign specifications for briquetted fuel2 ,no4 #cff1 ,tests of coal and briquettes as fuel for house-heating boilers2 ,no4 #cfg1 ,significance of drafts in steam-boiler practice2 ,no4 #cfh1 ,coking and washing tests of coal at ,denver2 ,no4 #cgc1 ,smokeless combustion of coal in boiler plants1 with a chapter on central heating plants2 ,no4 #cgh1 ,results of purchasing coal under ,government specifications2 ,no4 #chb1 ,the effect of oxygen in coal2 and1 ,no4 #che1 ,briquetting tests at ,norfolk1 ,va4 ,,discussion ,,kenneth ,,allen1 ,m4 ,am4 ,soc4 ,c4 ,e4--,the speaker would like to know whether anything has been done in the ,united ,states toward utilizing marsh mud for fuel4 ,in an address by ,mr4 ,edward ,atkinson1 before the ,new ,england ,water ,works ,association1 in #aijd1 on the subject of 8,bog ,fuel10 he referred to its extensive use in ,sweden and elsewhere1 and intimated that there was a wide field for its use in ,america4 ,the percentage of combustible material in the mud of ordinary marsh lands is very considerable1 and there are enormous deposits readily available2 but it is hardly probable that its calorific value is sufficiently high to render its general use at this time profitable4 ,as an example of the amount of organic matter which may remain stored in these muds for many years1 the speaker would mention a sample taken from the bottom of a trench1 which he had analyzed a few years ago4 ,although taken from a depth of about #ae ft41 much of the vegetable fiber remained intact4 ,the material proved to be #gj volatile4 ,possibly before the existing available coal deposits are exhausted1 the exploitation of meadow muds for fuel may become profitable4 ,,henry ,,kreisinger1 ,esq4#bi 7by letter74--,mr4 ,wilson gives a brief description of a long furnace and an outline of the research work which is being done in it4 ,it may be well to discuss somewhat more fully the proposed investigations and point out the practical value of the findings to which they may lead4 ,in general1 the object is to study the process of combustion of coal4 ,when soft coal is burned in any furnace1 part of the combustible is driven off shortly after charging1 and has to be burned in the space between the fuel bed and the exit of the gases1 which is called the combustion space4 ,there is enough evidence to show that1 with a constant air supply1 the completeness of the combustion of the volatile combustible depends on the length of time the latter stays within the combustion space2 but1 with a constant rate of charging the coal1 this length of time depends directly on the extent of the combustion space4 ,thus1 if the volume of the volatile combustible evolved per second and the admixed air is #dj cu4 ft41 and the extent of the combustion space is #hj cu4 ft41 the average time the gas will stay within the latter is #b sec42 if the combustion space is #bj cu4 ft41 the average time the mixture can stay in this space is only sec41 and its combustion will be less complete than in the first case4 ,thus it is seen that the extent of the combustion space of a furnace is an important factor in the economic combustion of volatile coals4 ,the specific object of the investigations1 thus far planned1 is to determine the extent of the combustion space required to attain practically complete combustion when a given quantity of a given coal is burned under definite conditions4 ,with this object in view1 the furnace has been provided with a combustion space large enough for the highest volatile coals and for the highest customary rate of combustion4 ,to illustrate the application of the data which will be obtained by these experiments1 the following queries are given3 ,suppose it is required to design a furnace which will burn coal from a certain ,illinois mine at the rate of #a1jjj lb4 per hour1 with a resulting temperature of not less than #b1hjj ,fahr4 ,how large a combustion space is required to burn1 with practical completeness1 the volatile combustible8 ,what completeness of combustion can be attained1 if the combustion space is only three-fourths of the required extent8 ,in the present state of the knowledge of the process of combustion of coal1 these queries cannot be answered definitely4 ,in the literature on combustion one may find statements that the gases must be completely burned before leaving the furnace or before they strike the cooling surfaces of the boiler2 but there is no definite information available as to how long the gases must be kept in the furnace or how large the combustion space must be in order to obtain practically complete combustion4 ,it is strange that so little is known of such an old art as the combustion of coal4 ,the research work under consideration is fundamentally a problem in physical chemistry1 and1 for that reason1 has been assigned to a committee consisting of the writer as ,engineer1 ,dr4 ,j4 ,c4 ,w4 ,frazer1 ,chemist1 and ,dr4 ,j4 ,k4 ,clement1 ,physicist4 ,the outcome of the investigation may prove of extreme interest to mechanical and fuel engineers1 and to all who have anything to do with the burning of coal or the construction of furnaces4 ,in the experiments thus far planned the following factors will be considered3 ,effect of the ,nature of ,coal on the ,extent of ,combustion ,space ,required4--,the steaming coals mined in different localities evolve different volumes of volatile combustible1 even when burned at the same rate4 ,the coal which analyzes #de of volatile matter evolves a much greater volume of gases and tar vapors than that analyzing only #ae per cent4 ,these evolved gases and tar vapors must be burned in the space4 ,consequently1 a furnace burning high volatile coal must have a much larger combustion space than that burning coal low in volatile combustible4 ,there is enough evidence to show that the extent of combustion space required to burn the volatile combustible depends1 not only on the volume of the combustible mixture1 but also on the chemical composition of the volatile combustible4 ,thus the volatile combustible of low volatile coal1 when mixed with an equal volume of air1 may require #a sec4 in the combustion space to burn practically to completeness1 while it may require #b sec4 to burn the same volume of the volatile combustible of high volatile coal with the same completeness2 so that the extent of the combustion space required to burn various kinds of coal may not be directly proportional to the volatile matter of the coal4 ,effect of the ,rate of ,combustion on the ,extent of ,combustion ,space ,required4--,with the same coal1 the volume of the volatile combustible distilled from the fuel bed per unit of time varies as the rate of combustion4 ,thus1 when this rate is double that of the standard1 the volume of gases and tar vapors driven from the fuel is about doubled4 ,to this increased volume of volatile combustible1 about double the volume of air must be added1 and1 if the mixture is to be kept the same length of time within the combustion space1 the latter should be about twice as large as for the standard rate of combustion4 ,thus the combustion space required for complete combustion varies1 not only with the nature of the coal1 but also with the rate of firing the fuel1 which1 of course1 is self-evident4 ,effect of ,air ,supply on the ,extent of ,combustion ,space ,required4--,another factor which influences the extent of the combustion space is the quantity of air mixed with the volatile combustible4 ,perhaps1 within certain limits1 the combustion space may be decreased when the supply of air is increased4 ,however1 any statement at present is only speculation2 the facts must be determined experimentally4 ,one fact is known1 namely1 that1 in order to obtain higher temperatures of the products of combustion1 the air supply must be decreased4 ,effect of ,rate of ,heating of ,coal on the ,extent of ,combustion ,space ,required4--,there is still another factor1 a very important one1 which1 with a given coal and any given air supply1 will influence the extent of the combustion space4 ,this factor is the rate of heating of the coal when feeding it into the furnace4 ,the so-called 8proximate0 analysis of coal is indeed only very approximate4 ,when the analysis shows1 say1 #dj of volatile matter and #de of fixed carbon1 it does not mean that the coal is actually composed of so much volatile matter and so much fixed carbon2 it simply means that1 under a certain rate of heating attained by certain standard laboratory conditions1 #dj of the coal has been driven off as 8volatile matter40 ,if the rate or method of heating were different1 the amount of volatile matter driven off would also be different4 ,chemists state that it is difficult to obtain accurate checks on 8proximate0 analysis4 ,to illustrate this factor1 further reference may be made to the operation of the up-draft bituminous gas producers4 ,in the generator of such producers the tar vapors leave the freshly fired fuel1 pass through the wet scrubber1 and are finally separated by the tar extractor as a black1 pasty substance in a semi-liquid state4 ,if this tar is subjected to the standard proximate analysis1 it will be shown that from #dj to #ej of it is fixed carbon1 although it left the gas generator as volatile matter4 ,it is desired to emphasize the fact that different rates of heating of high volatile coals will not only drive off different percentages of volatile matter1 but that the latter itself varies greatly in chemical composition and physical properties as regards inflammability and rapidity of combustion4 ,thus it may be said that the extent of the combustion space required for the complete oxidation of the volatile combustible depends on the method of charging the fuel1 that is1 on how rapidly the fresh fuel is heated4 ,if this factor is given proper consideration1 it may be possible to reduce very materially the necessary space required for complete combustion4 ,the ,effect of the ,rate of ,mixing the ,volatile ,combustible and ,air on the ,extent of the ,combustion ,space4--,when studying the effects discussed in the preceding paragraphs1 the rate of mixing the volatile combustible with the supply of air must be as constant as practicable4 ,at first1 tests will be made with no special mixing devices1 the mixing will be accomplished entirely by the streams of air entering the furnace at the stoker1 and by natural diffusion4 ,although there appears to be violent stirring of the gases above the fuel bed1 the mixture of the gases does not become homogeneous until they are about #aj or #ae ft4 from the stoker4 ,the mixing caused by the air currents forced into the furnace at the stoker is very distinct1 and can be readily observed through the peep-hole in the side wall of the ,heine boiler1 opposite the long combustion chamber4 ,this mixing is shown in ,fig4 #bj4 ,a is a current of air forced from the ash-pit directly upward through the fuel bed2 ,b and ,b are streams of air forced above the fuel bed through numerous small openings at the furnace side of each hopper4 ,those currents cause the gases to flow out of the furnace in two spirals1 as shown in ,fig4 #bj4 ,the velocity of rotation on the outside of the two spirals appears to be about #aj ft4 per sec41 when the rate of combustion is about #gej lb4 of coal per hour4 ,it is reasonable to expect that when the rate of mixing is increased by building piers and other mixing structures immediately back of the grate1 the completeness of the combustion will be effected in less time1 and a smaller combustion space will be required4 ,thus1 the mixing structures may be an important factor in the extent of the required combustion space4 ,to sum up1 it can be said that the extent of the space required to obtain a combustion which can be considered complete for all practical purposes1 depends on the following factors3 7a74--,nature of coal1 7b74--,rate of combustion1 7c74--,supply of air1 7d74--,rate of heating fuel1 7e74--,rate of mixing volatile combustible and air4 ,just how much the extent of the combustion space required will be influenced by these factors is the object of the experiments under discussion4 ,the ,scope of the ,experiments4--,with this object in view1 as explained in the preceding paragraphs1 the following series of experiments are planned3 ,illustration3 ,fig4 #bj4 ,,section ,,through ,,stoker ,,showing ,,mixing ,,of ,,gases ,,caused ,,by ,,currents ,,of ,,air ,six or eight typical coals are to be selected1 each representing a certain group of nearly the same chemical composition4 ,each series will consist of several sets of tests1 each set being run with all the conditions constant except the one1 the effect of which on the size of the combustion space is to be investigated4 ,thus a set of four or five tests will be made1 varying in rate of combustion from #bj to #hj lb4 of coal per square foot of grate per hour1 keeping the supply of air per pound of combustible and the rate of heating constant4 ,this set will show the effect of the rate of combustion of the coal on the extent of space required to obtain combustion which is practically complete4 ,other variables1 such as composition of coal1 supply of air1 and rate of heating1 remain constant4 ,another set of four or five tests will be made with the same coal and at the same rate of combustion1 but the air supply will be different for each test4 ,this set of tests will be repeated for two or three different rates of combustion4 ,thus each of these sets will give the effect of the air supply on the extent of combustion space when the coal and rate of combustion remain constant4 ,still another set of tests should be made in which the time of heating the coal when feeding it into the furnace will vary from #c to #cj min4 ,in each of the tests of this set1 the rate of combustion and the air supply will be kept constant1 and the set will be repeated for two or three rates of combustion and two or three supplies of air4 ,each of these sets of tests will give the effect of the rate of heating of fresh fuel on the extent of combustion space required to burn the distilled volatile combustible4 ,these sets of experiments will require a modification in the stoker mechanism1 and1 on that account1 may be put off until all the other tests on the other selected typical coals are completed4 ,as the investigation proceeds1 enough may be learned so that the number of tests in each series may be gradually reduced4 ,after all the desirable tests are made with the furnace as it stands1 several kinds of mixing structures will be built successively back of the stoker and tried1 one kind at a time1 with a set of representative tests4 ,thus the effectiveness of such mixing structures will be determined4 ,determining the ,completeness of ,combustion4--,the completeness of combustion in the successive cross-sections of the stream of gases is determined mainly by the chemical analysis of samples of gases collected through the openings at these respective cross-sections4 ,the first of these cross-sections at which gas samples are collected1 passes through the middle of the bridge wall2 the others are placed at intervals of #e ft4 through the entire length of the furnace4 ,measurements of the temperature of the gases1 and direct observations of the length and color of the flames and of any visible smoke will be also made through the side peep-holes4 ,these direct observations1 together with the gas analysis1 will furnish enough data to determine the length of travel of the combustible mixture to reach practically complete combustion4 ,in other words1 these observations will determine the extent of the combustion space for various kinds of coal when burned under certain given conditions4 ,direct observations and the analysis of gases at sections nearer the stoker than that at which the combustion is practically complete1 will show how the process of combustion approaches its completion4 ,this information will be of extreme value in determining the effect of shortening the combustion space on the loss of heat due to incomplete combustion4 ,method of ,collecting ,gas ,samples4--,the collection of gas samples is a difficult problem in itself1 when one considers that the temperature of the gases1 as they are in the furnace1 ranges from #b1djj to #c1bjj ,fahr42 consequently1 the samples must be collected with water-cooled tubes4 ,thus far1 about #be preliminary tests have been made4 ,these tests show that the composition of the gases at the cross-sections near the stoker is not uniform1 and that more than one sample must be taken from each cross-section4 ,it was decided to take #i samples from the cross-section immediately back of the stoker1 and reduce the number in the sections following1 according to the uniformity of the gas composition4 ,thus1 about #ce simultaneous gas samples must be taken for each test4 ,the samples will be subjected1 not only to the usual determination of ,,co#b1 ,o#b and ,,co1 but to a complete analysis4 ,it is also realized that some of the carbon-hydrogen compounds which1 at the furnace temperature1 exist as heavy gases1 are condensed to liquids and solids when cooled in the sampling tubes1 where they settle and tend to clog it4 ,to neglect the presence of this form of the combustible would introduce considerable error in the determination of the completeness of combustion at any of the cross-sections4 ,therefore1 special water-cooled sampling tubes are constructed and equipped with filters which separate the liquid and solid combustible from the gases4 ,the contents of these filters are then also subjected to complete analysis4 ,to obtain quantitative data1 a measured quantity of gases must be drawn through these filtering sampling tubes4 ,the ,measuring of ,temperatures4--,at present the only possible known method of measuring the temperature of the furnace gases is by optical and radiation pyrometers4 ,platinum thermo-couples are soon destroyed by the corrosive action of the hot gases4 ,the pyrometers used at present are the ,wanner optical pyrometer and the ,fery radiation pyrometer4 ,the ,flow of ,heat ,through ,furnace ,walls4--,an interesting side investigation has developed1 in the study of the loss of heat through the furnace walls4 ,in the description of this experimental furnace it has been said that the side walls contained a #b-;in4 air space1 which1 in the roof1 was replaced with a #a-;in4 layer of asbestos4 ,to determine the relative resistance to heat flow of the air space and the asbestos layer1 #bj thermo-couples were embedded1 in groups of four1 to different depths at three places in the side wall and at two places in the roof4 ,in the side wall1 one of the thermo-couples of each group was placed in the inner wall near the furnace surface2 the second thermo-couple was placed in the same wall1 but near the surface facing the air space2 the third thermo-couple was placed in the outer wall near the inner surface2 and the fourth was placed near the outer surface in the outer wall4 ,in the roof the second and third thermo-couples were placed in the brick near the surface on each side of the asbestos layer4 ,these thermo-couples have shown that the temperature drop across the #b-;in4 air space was much less than that across the #a-;in4 layer of asbestos2 in fact1 that it was considerably less than the temperature drop through the same thickness of the brick wall4 ,the results obtained prove that1 as far as heat insulation is concerned1 air spaces in furnace walls are undesirable4 ,the heat is not conducted through the air1 but leaps across the space by radiation4 ,in furnace construction a solid wall is a better heat insulator than one of the same total thickness containing an air space4 ,if it is necessary to build a furnace wall in two parts on account of unequal expansion1 the space between the two walls should be filled with some solid1 cheap1 non-conducting materials1 such as ash1 sand1 or crushed brick4 ,a more detailed account of these experiments may be found in a ,bulletin of the ,u4,s4 ,geological ,survey entitled 8,the ,flow of ,heat ,through ,furnace ,walls40 ,,walter ,o4 ,,snelling1 ,esq4#cj 7by letter74--,the work of the ,united ,states ,testing ,station at ,pittsburg has been set forth so fully by ,mr4 ,wilson that a further statement as to the results achieved may seem like repetition4 ,it would be most unlikely1 however1 that studies of such variety should possess no other value than along the direct lines being investigated4 ,in the case of the ,mine ,accidents ,division1 at least1 it is certain that the indirect benefits of some of the studies have been far-reaching1 and are now proving of value in lines far removed from those which were the primary object of the investigation4 ,they are developing facts which will be of great value to all engineers or contractors engaged in tunneling or quarrying4 ,as the writer's experience has been solely in connection with the chemical examination of explosives1 he will confine his discussion to this phase4 ,in studying the properties of various explosives1 and in testing work to separate those in which the danger of igniting explosive mixtures of coal dust and air1 or of fire-damp and air1 is greatest1 from those in which this danger is least1 much information has been collected4 ,mr4 ,wilson has described many of the tests1 and it can be readily seen that in carrying out these and other tests on each of the explosives submitted1 a great many facts relating to the properties of explosive compounds have been obtained1 which were soon found to be of decided value in directions other than the simple differentiation of explosives which are safe from those which are unsafe in the presence of explosive mixtures of fire-damp or coal dust4 ,the factors which determine the suitability of an explosive for work in material of any particular physical characteristics depend on the relationship of such properties as percussive force 7or the initial blow produced by the products of the decomposition of the explosive at the moment of explosion71 and the heaving force 7or the continued pressure produced by the products of the decomposition1 after the initial blow at the instant of detonation74 ,where an explosive has been used in coal or rock of a certain degree of brittleness1 and where the work of the explosive with that particular coal is not thoroughly satisfactory1 it becomes evident that through the systematic use of the information available at the ,testing ,station 7and now in course of publication in the form of bulletins71 in regard to the relationship between percussive and heaving forces in different explosives1 as shown by the tests with small lead blocks1 the ,trauzl test1 and the ballistic pendulum1 that explosives can be selected which1 possessing in modified form the properties of the explosive not entirely satisfactory in that type of coal or rock1 would combine all the favorable properties of the first explosive1 together with such additional advantages as would come from its added adaptation to the material in which it is to be used4 ,for example1 if the explosive in use were found to have too great a shattering effect on the coal1 an examination of the small lead-block test of this explosive1 and a comparison of this with lead-block tests of other explosives having practically the same strength1 as shown by the ballistic pendulum1 will enable the mine manager to select from those already on the ,permissible ,list 7and therefore vouched for in regard to safety in the presence of gas and coal dust1 when used in a proper way71 some explosive which will have the same strength1 and yet which1 because of lessened percussive force or shattering effect1 will produce coal in the manner desired4 ,if one takes the other extreme1 and considers a mine in which the product is used exclusively for the preparation of coke 7and therefore where shattering of the coal is in no way a disadvantage71 the mine superintendent's interest will be primarily to select an explosive which1 as indicated by suitable lead-block1 ,trauzl1 and ballistic pendulum tests1 will produce the greatest amount of coal at the least cost4 ,as the cost of the explosive does not form any part of the tables prepared by the ,testing ,station1 the relative cost must be computed from the manufacturer's prices1 but the results tabulated by the ,station will contain all the other data necessary to give the mine superintendent 7who cares to take the small amount of trouble necessary to familiarize himself with the tables7 all the information which is required to compare the action of one explosive with that of any other explosive tested4 ,in this way it is seen that1 aside from the primary consideration of safety in the presence of explosive mixtures of fire-damp and coal dust 7a condition alike fulfilled by all explosives admitted to the ,permissible ,list71 the data prepared by the ,testing ,station also give the information necessary to enable the discriminating mine manager to select an explosive adapted to the particular physical qualities of the coal at his mine1 or to decide intelligently between two explosives of the same cost on the basis of their actual energy content in the particular form of the heaving or percussive force required in his work4 ,up to the present time the investigations have been confined to explosives used in coal mining1 because the ,act of ,congress establishing the ,testing ,station has thus limited its work4 ,accordingly1 it is not possible to compare1 on the systematic basis just mentioned1 the explosives generally used in rock work4 ,it is probable that1 if the ,bill now before ,congress in regard to the establishment of a ,bureau of ,mines is passed1 work of this character will be undertaken1 and the tables of explosives now prepared will be extended to cover all those intended for general mining and quarrying use4 ,data of such character are unobtainable to-day1 and1 as a result1 a considerable percentage of explosives now used in all mining operations is wasted1 because of their lack of adaptation to the materials being blasted4 ,it is well known1 for example1 that when an explosive of high percussive force is used in excavating in a soft or easily compressed medium1 a considerable percentage of its force is wasted as heat energy1 performing no other function than the distortion and compression of the material in which it is fired1 without exerting either an appreciable cracking or fissuring effect1 or a heaving or throwing of the material4 ,owing to lack of information in regard to the exact relationship between the percussive and the heaving force in particular explosives1 this waste1 as compared with the quantity required for the work with a properly balanced material1 will continue2 but it is to be hoped that it will soon be possible to give the mining and quarrying industries suitable information in regard to the properties of the various explosives1 so that the railroad contractor and the metal miner may have the same simple and exact means of discrimination between suitable and unsuitable explosives that is now being provided for the benefit of the coal miner4 ,another of the important but indirect benefits of this work has been the production of uniformity of strength and composition in explosives4 ,an example of this helpful influence is the standardization of detonating caps and electric detonators4 ,in the early days of the explosive industry1 it was apparently advantageous for each manufacturer to have a separate system of trade nomenclature by which to designate the strengths of the different detonators manufactured by him4 ,the necessity and even the advantage of such methods have long been outgrown1 and yet1 until the past year1 the explosive industry has had to labor under conditions which made it almost impossible for the user of explosives to compare1 in cost or strength1 detonators of different manufacturers2 or to select intelligently the detonator best suited to the explosive to be used4 ,after conference with the manufacturers of detonating caps and electric detonators1 a standard system of naming the strengths of these products has been selected by the ,testing ,station1 and has met with a most hearty response4 ,it is encouraging to note that1 in recent trade catalogues1 detonators are named in such a way as to enable the user to determine directly the strength of the contained charge1 which is a decided advantage to every user of explosives and also to manufacturers4 ,the uniformity of composition of explosives 7and many difficulties in mining work and many accidents have been rightly or wrongly attributed to lack of uniformity7 may be considered as settled in regard to all those on the ,permissible ,list4 ,one of the conditions required of every explosive on that list is that its composition must continue substantially the same as the samples submitted originally for official test4 ,up to the present1 all explosives admitted to the ,permissible ,list have maintained their original composition1 as determined by subsequent analyses of samples selected from mines in which the explosive was in use1 and comparison with the original samples4 ,the data assembled by the ,testing ,station in regard to particular explosives have also been of great benefit to the manufacturers4 ,when the explosives tests were commenced1 comparatively few explosives were being made in the ,united ,states for which it was even claimed by the manufacturers that they were at all safe in the presence of explosive mixtures of gas or coal dust4 ,it was evident that1 without systematic tests1 very little knowledge of the safety or lack of safety of any particular explosive could ever be gained1 and1 consequently1 the user of explosives was apt to regard with incredulity any claim by the manufacturer in regard to the qualities of safety4 ,owing to lack of proof1 this was most natural2 and it was also evident that the very slow process of testing1 which was offered by a study of mine explosions during past years1 was sufficient only to prove the danger of black powder1 and not in any way to indicate the safety of any of the brands of mining powder for which this property was claimed4 ,indeed1 one of the few explosives to which the name1 8safety10 was attached1 at the time the ,government experiments were first undertaken1 was found to be anything but safe when tested in the gallery1 although there is no reason to believe that the makers of this and other explosives claiming 8safety0 for their product1 did not have the fullest confidence in their safety4 ,the ,testing ,station offered the first opportunity in the ,united ,states to obtain facts in regard to the danger of any particular explosive in the presence of explosive mixtures of gas or coal dust4 ,with most commendable energy1 the manufacturers of explosives1 noting the early failures of their powders in the testing gallery1 began at once to modify them in such ways as suggested by the behavior of the explosives when under test1 and1 in a short time1 returned to the ,testing ,station with improved products1 able to stand the severe tests required4 ,in this way the ,testing ,station has been a most active agent in increasing the general safety of explosives1 and the manufacturers have shown clearly that it never was their desire to offer inferior explosives to the public1 but that their failures in the past were due solely to lack of information in regard to the action of explosives under the conditions which exist before a mine disaster4 ,the chance being offered to duplicate1 at the ,testing ,station1 the conditions represented in a mine in the presence of gas1 they showed an eagerness to modify and improve their explosives so as to enable them to answer severe mining conditions1 which is most commendable to ,american industry4 ,in regard to the unfavorable conditions existing in mines in the past1 the same arguments may be used4 ,in spite of the frequency of mine accidents in the ,united ,states1 and in spite of the high death rate in coal mining as compared with that in other countries1 it must be said in fairness that this has been the result of ignorance of the actual conditions which produce mine explosions1 rather than any willful disregard of the known laws of safety by mine owners4 ,conditions in ,american mines are far different from those obtaining in mines abroad1 and1 as a result1 the rules which years of experience had taught to foreign colliery managers were not quickly applied to conditions existing in ,american mines2 but1 as soon as the work at the ,pittsburg ,station had demonstrated the explosibility of the coal dust from adjoining mines1 and had shown the very great safety of some explosives as compared with others1 there was at once a readiness on the part of mine owners throughout the country to improve conditions in their mines1 and to take advantage of all the studies made by the ,government1 thus showing clearly that the disasters of the past had been due to lack of sufficient information rather that to any willful disregard of the value of human lives4 ,another of the indirect benefits of the work of the ,station has resulted from its examination of explosives for the ,panama ,canal4 ,for several years the ,isthmian ,canal ,commission has been one of the largest users of explosives in the world1 and1 in the purchase of the enormous quantities required1 it was found necessary to establish a system of careful examination and inspection4 ,this was done in order to insure the safety of the explosives delivered on the ,isthmus1 and also to make certain that the standards named in the contract were being maintained at all times4 ,with its established corps of chemists and engineers1 it was natural that this important work should be taken up by the ,technologic ,branch of the ,united ,states ,geological ,survey1 and1 during the past three years1 many millions of pounds of dynamite have been inspected and samples analyzed by the chemists connected with the ,pittsburg ,testing ,station1 thus insuring the high standard of these materials4 ,one of the many ways in which this work for the ,canal ,commission has proved of advantage is shown by the fact that1 as a result of studies at the ,testing ,station1 electric detonators are being made to-day which1 in water-proof qualities1 are greatly superior to any similar product4 ,as the improvements of these detonators were made by a member of the testing staff1 all the pecuniary advantages arising from them have gone directly to the ,government1 which to-day is obtaining superior electric detonators1 and at a cost of about one-third of the price of the former materials4 ,all the work of the ,technologic ,branch is being carried out along eminently practical lines1 and is far removed from such work as can be taken up advantageously by private or by ,state agencies4 ,the work of the ,mine ,accidents ,division was taken up primarily to reduce the number of mine accidents1 and to increase the general conditions of safety in mining4 ,as the work of this ,division has progressed1 it has been found to be of great advantage to the miner and the mine owner1 while the ultimate results of the studies will be of still greater value to every consumer of coal1 as they will insure a continued supply of this valuable product1 and at a lower cost than if the present methods1 wasteful alike in lives and in coal1 had been allowed to continue for another decade4 ,a4 ,,bartoccini1 ,assoc4 ,m4 ,am4 ,soc4 ,c4 ,e4 7by letter74--,the writer made a personal investigation of the mine disaster of ,cherry1 ,ill4 ,he interviewed the men who escaped on the day of the accident1 and also several of those who were rescued one week later4 ,he also interrogated the superintendent and the engineer of the mine1 and obtained all the information asked for and also the plans of the mine showing the progress of the work4 ,after a careful investigation the writer found that the following conditions existed at the mine at the time of the disaster3 ,first4--,there were no means for extinguishing fires in the mine4 ,second4--,there were no signal systems of any kind4 ,had the mine been provided with electric signals and telephones1 like some of the most modern mines in the ,united ,states1 the majority of the men could have been saved1 by getting into communication with the outside and working in conjunction with the rescuers4 ,third4--,the miners had never received instructions of how to behave in case of fire4 ,fourth4--,the main entries and stables were lighted with open torches4 ,fifth4--,the organization of the mine was defective in some way1 for at the time of the disaster orders came from every direction4 ,sixth4--,the air shaft was used also as a hoisting shaft4 ,seventh4--,the main shaft practically reached only to the second vein2 its extension to the third and deepest vein was not used4 ,eighth4--,plans of the workings of the second and third veins were not up to date4 ,the last survey recorded on them was that of ,june1 #aiji4 ,this would have made rescue work almost impossible to men not familiar with the mine4 ,ninth4--,the inside survey of the mine was not connected with the outside survey4 ,would it not be possible for the ,united ,states ,geological ,survey to enforce rules which would prevent the existence of conditions such as those mentioned8 ,the ,survey is doing wonderful work1 as shown by the rescue of twenty miners at ,cherry one week after the conflagration2 but there is no doubt that perhaps all the men could have been saved if telephone communications with the outside had been established4 ,telephone lines to resist any kind of a fire1 can easily be installed1 and the expense is small1 almost negligible when one considers the enormous losses suffered by the mine owners and by the families of the victims4 ,h4 ,g4 ,,stott1 ,m4 ,am4 ,soc4 ,c4 ,e4--,the curves shown by ,mr4 ,wilson give a clear general idea of the relative efficiencies of steam and gas engines when treated from a purely theoretical thermodynamic point of view4 ,this point of view1 however1 is only justified when small units having a maximum brake horse-power not exceeding #a1jjj are considered4 ,the steam engine or turbine operating under a gauge pressure of #bjj lb4 per sq4 in41 and with #aej superheat1 has a maximum temperature of #ech ,fahr4 in its cylinder1 while that of the gas engine varies between #b1jjj and #c1jjj ,fahr4 ,the lubrication of a surface continually subjected to the latter temperature would be impossible1 so that water jackets on the cylinders and1 in the larger units1 in the pistons become absolutely necessary4 ,as the cylinders increase in diameter1 it is necessary1 of course1 to increase their strength in proportion to their area1 which1 in turn1 is proportional to the square of the diameter4 ,the cooling surface1 however1 is only proportional to the circumference1 or a single function of the diameter4 ,increasing the strength in proportion to the square of the diameter soon leads to difficulties1 because of the fact that the flow of heat through a metal is a comparatively slow process2 the thick walls of the cylinders on large engines cannot conduct the heat away fast enough1 and all sorts of strains are set up in the metal1 due to the enormous difference in temperature between the inside and the jacket lining of the cylinder4 ,these conditions produce cut and cracked cylinders1 with a natural resultant of high maintenance and depreciation costs4 ,these costs1 in some cases1 have been so great1 not only in the ,united ,states1 but in ,europe and ,africa1 as to cause the complete abandonment of large gas engine plants after a few years of attempted operation4 ,the first consideration in any power plant is that it shall be thoroughly reliable in operation1 and the second is that it shall be economical1 not only in operation1 but in maintenance and depreciation4 ,therefore1 in using the comparative efficiency curves shown in ,mr4 ,wilson's paper it should be kept in mind that the cost of power is not only the fuel cost1 but the fuel plus the maintenance and depreciation charges1 and that the latter items should not be taken from the first year's account1 but as an average of at least five years4 ,the small gas engine is a very satisfactory apparatus when supplied with good1 clean gas1 and when given proper attention1 but great caution should be used before investing in large units1 until further developments in the art take place1 as conservation of capital is just as important as conservation of coal4 ,b4 ,w4 ,,dunn1 ,esq4#ca 7by letter47--,the growing importance of investigations of explosives1 with a view to increasing the consumer's knowledge of proper methods for handling and using them1 is evident when it is noted that the total production of explosives in the ,united ,states has grown from less than #i1jjj1jjj lb4 in #ahdj to about #bae1jjj1jjj lb4 in #aije4 ,table #e has been compiled by the ,bureau of ,explosives of the ,american ,railway ,association4 ,,table #e4--,manufacture of ,explosives in the ,united ,states1 #aiji4 ---------------------------------------- ------------------------ ,kind of explosives4 ,number of ,maximum ,capacity1 in ,pounds4 factories4 ----------------------------- ,daily4 ,annual4 ---------------------------------------- ----------------------- ,black powder #di #a1bbj1aej #cff1ace1jjj ,high explosives #cg #a1bjc1ice #cfa1ahj1ejj ,smokeless powders #e #ge1fhf #bb1gje1hjj ---------------------------------------- ----------------------- ,the first problem presented by this phenomenal increase relates to the safe transportation of this material from the factories to points of consumption4 ,a package of explosives may make many journeys through densely populated centers1 and rest temporarily in many widely separated storehouses before it reaches its final destination4 ,a comprehensive view of the entire railway mileage of the ,united ,states would show at any instant about #e1jjj cars partially or completely loaded with explosives4 ,more than #a1bjj storage magazines are listed by the ,bureau of ,explosives as sources of shipments of explosives by rail4 ,the increase in the demand for explosives has not been due entirely to the increase in mining operations4 ,the civil engineer has been expanding his use of them until now carloads of dynamite1 used on the ,isthmus of ,panama in a single blast1 bring to the steam shovels as much as #ge1jjj cu4 yd4 of material1 the dislodgment of which by manual labor would have required days of time and hundreds of men4 ,without the assistance of explosives1 the construction of subways and the driving of tunnels would be impracticable4 ,even the farmer has awakened to the value of this concentrated source of power1 and he uses it for the cheap and effective uprooting of large stumps over extended areas in ,oregon1 while an entire acre of subsoil in ,south ,carolina1 too refractory for the plow1 is broken up and made available for successful cultivation by one explosion of a series of well-placed charges of dynamite4 ,it has also been found by experience that a few cents' worth of explosive will be as effective as a dollar's worth of manual labor in preparing holes for transplanting trees4 ,the use of explosives in war and in preparation for war is now almost a negligible quantity when compared with the general demand from peaceful industries4 ,with the completion of the ,panama ,canal1 it is estimated that the ,government will have used in that work alone more explosives than have been expended in all the battles of history4 ,until a few years ago little interest was manifested by the public in safeguarding the manufacture1 transportation1 storage1 and use of explosives4 ,anyone possessing the necessary degree of ignorance1 or rashness1 was free to engage in their manufacture with incomplete equipment2 they were transported by many railroads without any special precautions2 the location of magazines in the immediate vicinity of dwellings1 railways1 and public highways1 was criticized only after some disastrous explosion2 and the often inexperienced consumer was without access to a competent and disinterested source of information such as he now has in the testing plant at ,pittsburg so well described by ,mr4 ,wilson4 ,the first general move to improve these conditions is believed to have been made by the ,american ,railway ,association in ,april1 #aije4 ,it resulted in the organization of a ,bureau of ,explosives which1 through its inspectors1 now exercises supervision over the transportation of all kinds of dangerous articles on #bbc1fcj of the #bde1jjj miles of railways in the ,united ,states and ,canada4 ,a general idea of the kind and volume of inspection work is shown by the following extracts from the ,annual ,report of the ,chief ,inspector1 dated ,february1 #aiaj3 #aiji4 #aijh4 8,total number of railway lines members of ,bureau ,december #cast #agb #aeh ,total mileage of ,bureau lines ,december #cast #bji1ihd #bjb1ahf ,total number of inspections of stations for explosives #f1iec #e1fjc ,number of stations receiving two or more inspections for explosives #a1hci #a1cji ,total number of inspections of stations for inflammables #f1iej #a1jih ,number of stations receiving two or more inspections for inflammables #a1hhf 4444 ,total number of inspections of factories #bgh #bgj ,number of factories receiving two or more inspections #ge #fi ,total number of inspections of magazines #a1bic #a1edj ,number of magazines receiving two or more inspections #cdi #cfa ,total number of boxes of high explosives condemned as unsafe for transportation #aj1jbi #d1heb ,total number of kegs of black powder condemned as unsafe for transportation #a1dfh #eca ,total number of cars in transit containing explosives inspected #dge #ddh ,total number of cars in transit showing serious violations of the regulations #afh #aig ,total number of inspections of steamship companies' piers 7inflammable1 #ge2 explosive1 #fc7 #ach 4444 ,total number of inspections made by ,bureau #af1jhg #h1iei ,total number of lectures to railway officials and employes and meetings addressed on the subject of safe transportation of explosives and other dangerous articles #bae #aga #aiji4 #aijh4 #aijg4 8,total number of accidents resulting in explosions or fires in transportation of explosives by rail #ab #bb #gi ,total known property loss account explosions or accidents in transporting explosives by rail #b1fgc #aad1fbi #dif1hbj ,total number of persons injured by explosions in transit #g #ec #hj ,total number of persons killed by explosions in transit #f #bf #eb 8,during the same period reports have been rendered to the ,chief ,inspector by the ,chemical ,laboratory of the ,bureau on #gcd samples1 as follows3 ,explosives #baa ,fireworks #ahf ,inflammables #cjd ,paper for lining high explosive boxes #ca ,ammunition #b ---- ,total #gcd 8,as a means of ensuring the uniform enforcement of the regulations1 by a well grounded appreciation of their significance and application1 the lectures delivered by representatives of the ,bureau have proved most successful4 ,the promulgation of the regulations is not of itself sufficient to ensure uniformity or efficiency in their observance1 and so these lectures form a valuable supplement to the inspection service4 ,they have been successfully continued throughout the year1 and the requests for the delivery of them by the managements of so many of the membership lines1 is a convincing testimonial of the high esteem in which they are held4 8,while the lectures are primarily intended for the instruction and information of the officials and employes of the railway companies1 and especially of those whose duties bring them into immediate contact with the dangerous articles handled in transportation1 the manufacturers and shippers are invited1 and they have attended them in considerable numbers4 ,many of this class have voluntarily expressed their commendation of the lectures as a medium of education1 and signified their approval of them in flattering terms4 8,the scope of these lectures embraces elementary instruction in the characteristics of explosives and inflammables and the hazards encountered in their transportation and in what respects the regulations afford protection against them4 ,the requirements of the law1 and the attendant penalties for violation1 are fully described4 ,methods of preparation1 packing1 marking1 receiving1 handling and delivering1 are explained by stereopticon lantern slides4 ,these are interesting of themselves1 and are the best means of stamping the impression they are intended to convey upon the minds of the audiences1 and are always an acceptable feature of the lectures4 ,the reception generally given to the lectures by those who have attended them1 often at the voluntary surrender of time intended for rest while off duty1 may be stated as an indication that the subject matter is one in which they are interested4 8,the facilities of the ,young ,men's ,christian ,association1 in halls1 lanterns and skilled lantern operators1 have been generously accorded and made use of to great advantage1 in connection with the lectures at many places4 ,the co-operation of this ,association affords a convenient and economical method of securing the above facilities1 and the ,association has expressed its satisfaction with the arrangement as in line with the educational features which they provide for their members4 8,during the year #aiji1 #bae lectures were delivered at various points throughout the ,united ,states40 ,the ,bureau of ,explosives1 of the ,american ,railway ,association1 and the ,bureau of ,mines1 of the ,united ,states ,geological ,survey1 were independent products of a general agitation due to the appreciation by a limited number of public-spirited citizens of the gravity of the 8explosive0 problem4 ,it is the plain duty of the average citizen to become familiar with work of this kind prosecuted in his behalf4 ,he may be able to help the work by assisting to overcome misguided opposition to it4 ,evidences of this opposition may be noted in the efforts of some shippers to avoid the expense of providing suitable shipping containers for explosives and inflammable articles1 and in the threats of miners' labor unions to strike rather than use permissible explosives instead of black powder in mining coal in gaseous or dusty mines4 ,too much credit cannot be given ,messrs4 ,holmes and ,wilson1 and other officials of the ,technologic ,branch of the ,united ,states ,geological ,survey1 for the investigations described in this paper4 ,they are establishing reasonable standards for many structural materials2 they are teaching the manufacturer what he can and should produce1 and the consumer what he has a right to demand2 with scientific accuracy they are pointing the way to a conservation of our natural resources and to a saving of life which will repay the nation many times for the cost of their work4 ,when these facts become thoroughly appreciated and digested by the average citizen1 these gentlemen and their able assistants will have no further cause to fear the withdrawal of financial or moral support for their work4 ,,herbert ,m4 ,,wilson1 ,m4 ,am4 ,soc4 ,c4 ,e4 7by letter74--,the ,fuel ,division of the ,united ,states ,geological ,survey has given considerable attention to the use of peat as a fuel for combustion under boiler furnaces1 in gas producers1 and for other purposes4 ,it is doubtless to this material that ,mr4 ,allen refers in speaking of utilizing 8marsh mud for fuel10 since he refers to an address by ,mr4 ,edward ,atkinson on the subject of 8,bog ,fuel0 in which he characterized peat by the more popular term 8marsh mud40 ,in ,europe1 where fuel is expensive1 #aj1jjj1jjj tons of peat are used annually for fuel purposes4 ,a preliminary and incomplete examination1 made by ,mr4 ,c4 ,a4 ,davis1 of the ,fuel ,division of the ,geological ,survey1 indicates that the peat beds of the ,united ,states extend throughout an area of more than #aa1jjj sq4 miles4 ,the larger part of this is in ,new ,england1 ,new ,york1 ,minnesota1 ,wisconsin1 ,new ,jersey1 ,virginia1 and other ,coastal ,states which contain little or no coal4 ,it has been estimated that this area will produce #ac1jjj1jjj1jjj tons of air-dried peat4 ,at present peat production is in its infancy in the ,united ,states1 though there are in operation several commercial plants which find a ready market for their product and are being operated at a profit4 ,a test was made at the ,pittsburg plant on ,north ,carolina peat operated in a gas producer--the resulting producer gas being used to run a gas engine of #aej h4p4--the load on which was measured on a switch-board4 ,peat containing nearly #cj of ash and #ae of water gave #a commercial horse-power-hour for each #d lb4 of peat fired in the producer4 ,had the peat cost #b per ton to dig and prepare for the producer1 each horse-power-hour developed would have cost #j4d of a cent4 ,the fuel cost of running an electric plant properly equipped for using peat fuel1 of even this low grade1 in the gas producer would be about #d per #ajj h4p4 developed per #aj-;hour day4 ,equally good results were procured in tests of ,florida and ,michigan peat operated in the gas producer4 ,the investigations of peat under ,mr4 ,davis include studies of simple commercial methods of drying1 the chemical and fuel value1 analyses of the peat1 studies of the mechanical methods of digging and disintegrating the peat1 and physical tests to determine the strength of air-dried peat to support a load4 ,the calorific value of peat1 as shown by numerous analyses made by the ,united ,states ,geological ,survey1 runs from about #g1ejj to nearly #aa1jjj ,b4t4u41 moisture free1 including the ash1 which varies from less than #b to #bj1 the latter being considered in ,europe the limit of commercial use for fuel4 ,analyses of #be samples of peat from ,florida1 within these limits as to ash1 show a range of from #h1bfi to #aj1hfe ,b4t4u41 only four of the series being below #i1jjj ,b4t4u41 and four exceeding #aj1ejj ,b4t4u41 moisture free4 ,such fuel in ,florida is likely to be utilized soon1 since it only needs to be dug and dried in order to render it fit for the furnace or gas producer4 ,many bituminous coals now used commercially have fuel value as low as #aa1jjj ,b4t4u41 moisture free1 and with maximum ash content of #bj2 buckwheat anthracite averages near the same figures1 often running as high as #bd ash4 ,one bulletin concerning the peats of ,maine has been published1 and another1 concerning the peat industries of the ,united ,states1 is in course of publication4 ,mr4 ,bartoccini asks whether it would not be possible for the ,united ,states ,geological ,survey to enforce rules which would prevent the existence of conditions such as occurred at the mine disaster of ,cherry1 ,ill4 ,the ,united ,states ,government has no police power within the ,states1 and it is not within its province to enact or enforce rules or laws1 or even to make police inspection regarding the methods of operating mining properties4 ,the province of the mine accidents investigations and that of its successor1 the ,bureau of ,mines1 is1 within the ,states1 like that of other and similar ,government bureaus in the ,interior ,department1 the ,department of ,agriculture1 and other ,federal departments1 merely to investigate and disseminate information4 ,it remains for the ,states to enact laws and rules applying the remedies which may be indicated as a result of ,federal investigation4 ,investigations are now in progress and tests are being conducted with a view to issuing circulars concerning the methods of fighting mine fires1 the installation of telephones and other means of signaling1 and other subjects of the kind to which ,mr4 ,bartoccini refers4 ,much as the writer appreciates the kindly and sympathetic spirit of the discussion of ,messrs4 ,allen and ,bartoccini1 he appreciates even more that of ,colonel ,dunn and ,mr4 ,stott1 who are recognized authorities regarding the subjects they discuss1 and of ,messrs4 ,kreisinger and ,snelling1 who have added materially to the details presented in the paper relative to the particular investigations of which they have charge in ,pittsburg4 ,mr4 ,snelling's reference to the use of explosives in blasting operations should be of interest to all civil engineers1 as well as to mining engineers1 as should ,colonel ,dunn's discussion concerning the means adopted to safeguard the transportation of explosives4 ,since the presentation of the paper1 ,congress has enacted a law establishing1 in the ,department of the ,interior1 a ,united ,states ,bureau of ,mines4 ,to this ,bureau have been transferred from the ,geological ,survey the fuel-testing and the mine accidents investigations described in this paper4 ,to the writer it seems a matter for deep regret that the investigations of the structural materials belonging to and for the use of the ,united ,states1 were not also transferred to the same ,bureau4 ,on the last day of the session of ,congress1 a conference report transferred these from the ,geological ,survey to the ,bureau of ,standards4 ,it is doubtful whether the continuation of these investigations in that ,bureau1 presided over as it is by physicists and chemists of high scientific attainments1 will be of as immediate value to engineers and to those engaged in building and engineering construction as they would in the ,bureau of ,mines1 charged as it is with the investigations pertinent to the mining and quarrying industries1 and having in its employ mining1 mechanical1 and civil engineers4 ,,footnotes ,footnote #a3 ,presented at the meeting of ,april #bjth1 #aiaj4 ,footnote #b3 8,coal ,mine ,accidents10 by ,clarence ,hall and ,walter ,o4 ,snelling4 ,bulletin ,no4 #ccc1 ,u4,s4 ,geological ,survey1 ,washington1 ,d4,c4 ,footnote #c3 8,the ,explosibility of ,coal ,dust10 by ,george ,s4 ,rice and others4 ,bulletin ,no4 99 99 991 ,u4,s4 ,geological ,survey4 ,footnote #d3 8,notes on ,explosives1 ,mine ,gases and ,dusts10 by ,rollin ,thomas ,chamberlin4 ,bulletin ,no4 #chc1 ,u4,s4 ,geological ,survey1 #aiji4 ,footnote #e3 8,prevention of ,mine ,explosions10 by ,victor ,watteyne1 ,carl ,meissner1 and ,arthur ,desborough4 ,bulletin ,no4 #cfi1 ,u4,s4 ,geological ,survey4 ,footnote #f3 ,with a view to obtaining a dust of uniform purity and inflammability4 ,footnote #g3 8,the ,primer of ,explosives10 by ,c4 ,e4 ,munroe and ,clarence ,hall4 ,bulletin ,no4 #dbc1 ,u4,s4 ,geological ,survey1 #aiji4 ,footnote #h3 8,tests of ,permissible ,explosives10 by ,clarence ,hall1 ,w4 ,o4 ,snelling1 ,s4 ,p4 ,howell1 and ,j4 ,j4 ,rutledge4 ,bulletin ,no4 99 99 991 ,u4,s4 ,geological ,survey4 ,footnote #i3 8,structural ,materials ,testing ,laboratories10 by ,richard ,l4 ,humphrey1 ,bulletin ,no4 #cbi4 ,u4,s4 ,geological ,survey1 #aijh2 8,portland ,cement ,mortars and their ,constituent ,materials10 by ,richard ,l4 ,humphrey and ,william ,jordan1 ,jr41 ,bulletin ,no4 #cca1 ,u4,s4 ,geological ,survey1 #aijh2 8,strength of ,concrete ,beams10 by ,richard ,l4 ,humphrey1 ,bulletin ,no4 #cdd1 ,u4,s4 ,geological ,survey1 #aijh4 ,footnote #aj3 8,fire ,resistive ,properties of ,various ,building ,materials10 by ,richard ,l4 ,humphrey1 ,bulletin ,no4 #cgj1 ,u4,s4 ,geological ,survey1 #aiji4 ,footnote #aa3 8,purchasing ,coal ,under ,government ,specifications10 by ,j4 ,s4 ,burrows1 ,bulletin ,no4 #cgh1 ,u4,s4 ,geological ,survey1 #aiji4 ,footnote #ab3 8,experimental ,work in the ,chemical ,laboratory10 by ,n4 ,w4 ,lord1 ,bulletin ,no4 #cbc1 ,u4,s4 ,geological ,survey1 #aijg3 8,operations of the ,coal ,testing ,plant1 ,st4 ,louis1 ,mo40 ,professional ,paper ,no4 #dh1 ,u4,s4 ,geological ,survey1 #aijf4 ,footnote #ac3 ,also ,bulletins ,nos4 #bij1 #ccb1 #ccd1 #cfc1 #cff1 #cfg1 #cgc1 #djb1 #djc1 and #dab1 ,u4,s4 ,geological ,survey4 ,footnote #ad3 8,tests of ,coal for ,house ,heating ,boilers10 by ,d4 ,t4 ,randall1 ,bulletin ,no4 #ccf1 ,u4,s4 ,geological ,survey1 #aijh4 ,footnote #ae3 8,the ,smokeless ,combustion of ,coal10 by ,d4 ,t4 ,randall and ,h4 ,w4 ,weeks1 ,bulletin ,no4 #cgc1 ,u4,s4 ,geological ,survey1 #aiji4 ,footnote #af3 8,the ,flow of ,heat through ,furnace ,walls10 by ,w4 ,t4 ,ray and ,h4 ,kreisinger4 ,bulletin 7in press71 ,u4,s4 ,geological ,survey4 ,footnote #ag3 ,the assumption is made that a metal tube free from scale will remain almost as cool as the water2 actual measurements with thermo-couples have indicated the correctness of this assumption in the majority of cases4 ,footnote #ah3 8,heat ,transmission into ,steam ,boilers10 by ,w4 ,t4 ,ray and ,h4 ,kreisinger1 ,bulletin 7in press71 ,u4,s4 ,geological ,survey4 ,footnote #ai3 8,the ,producer ,gas ,power ,plant10 by ,r4 ,h4 ,fernald1 ,bulletin ,no4 #daf1 ,u4,s4 ,geological ,survey1 #aiji2 also ,professional ,paper ,no4 #dh and ,bulletins ,nos4 #bij1 #caf1 #ccb1 and #daf4 ,footnote #bj3 ,a ,taylor up-draft pressure producer1 made by ,r4 ,d4 ,wood and ,company1 ,philadelphia1 ,pa4 ,footnote #ba3 8,coal ,testing ,plant1 ,st4 ,louis1 ,mo410 by ,r4 ,h4 ,fernald1 ,professional ,paper ,no4 #dh1 ,vol4 ,,iii1 ,u4,s4 ,geological ,survey1 #aijf4 ,footnote #bb3 ,a report of these tests may be found in ,bulletin ,no4 99 99 991 ,u4,s4 ,geological ,survey4 ,footnote #bc3 8,illuminating ,gas ,coals10 by ,a4 ,h4 ,white and ,perry ,barker1 ,u4,s4 ,geological ,survey4 ,footnote #bd3 8,gasoline and ,alcohol ,tests10 by ,r4 ,m4 ,strong1 ,bulletin ,no4 #cib1 ,u4,s4 ,geological ,survey1 #aiji4 ,footnote #be3 8,washing and ,coking ,tests10 by ,richard ,moldenke1 ,a4 ,w4 ,belden and ,g4 ,r4 ,delamater1 ,bulletin ,no4 #ccf1 ,u4,s4 ,geological ,survey1 #aijh2 also1 8,washing and ,coking ,tests at ,denver1 ,colo410 by ,a4 ,w4 ,belden and ,g4 ,r4 ,delamater1 ,bulletin ,no4 #cfh1 ,u4,s4 ,geological ,survey1 #aiji4 ,footnote #bf3 ,u4,s4 ,geological ,survey1 ,professional ,paper ,no4 #dh1 ,pt4 ,,iii1 and ,bulletins ,nos4 #bij1 #ccb1 #ccf1 #cfh1 #che1 and #djc4 ,footnote #bg3 ,professional ,paper ,no4 #dh1 and ,bulletins ,nos4 #bij1 #caf1 #ccb1 #cdc1 #cfc1 #cff1 #che1 #djb1 #djc1 and #dab1 ,u4,s4 ,geological ,survey4 ,footnote #bh3 8,peat ,deposits of ,maine10 by ,e4 ,d4 ,bastin and ,c4 ,a4 ,davis4 ,bulletin ,no4 #cgf1 ,u4,s4 ,geological ,survey1 #aiji4 ,footnote #bi3 ,u4,s4 ,geological ,survey1 ,pittsburg1 ,pa4 ,footnote #cj3 ,chief ,explosives ,chemist1 ,u4,s4 ,geological ,survey4 ,footnote #ca3 ,lieutenant-,colonel1 ,ordnance ,dept41 ,u4 ,s4 ,a4 99 99 99 99 99 99 99 99 99 99 99 99 99 99 ,errata3 ,fig4 #c4 caption ,,safety ,,lamp ,,testing ,,gallery text reads 8,,safty0 ,mine-,rescue ,training experienced in rescue operations and familiar _/ with the conditions existing after mine disasters text reads 8familar0 so as to determine1 if possible1 the progress of combustion 7,fig4 #a1 ,plate ,,xviii74 text reads 8,pate ,,xviii0 ,the chemical analyses of the coals text reads 8anaylses0