IMAGE EVALUATION TEST TARGET (MT-3) 7. // //^.^^!i^^ A .V4 1.0 1.25 m 12.8 ■• I. 1^ 1.8 U 116 / '/ /^ HiotQgraphic Sciences Corporation 23 Vt'dST MAIN STREET WEBSTEff N.V. 14S8(> (716) 872 -..'Oa \ iS ^ %^^ # F.^ %^ i/.A CIHM/ICMH Microfiche Series. CIHIVI/ICIVIH Collection de microfiches. Canadian Institute for Historical Microreproductions / Institut Canadian de microreproductions historiques \ ^ !. Tschnicai and Bibliographic Notaa/Notas tachniquaa at bibliographiquaa IT to Tha inatituta haa attamptad to obtain tha baat original copy availabia for filming. Faaturaa of thia copy which may ba bibliogr&phically uniqua, which may altar any of tha tmagaa in tha raproduction, or which may aigntficantly changa tha uaual mathod of filming, ara (:hackad balow. D Colourad covara/ Couvartura da coulaur pn Covara damagad/ D D D D □ D Couvartura andommagia Covara raatorad and/or laminatad/ Couvartura raataurta at/ou palliculta r~1 Covar titia miaaing/ La titra da couvartura manqua Colourad mapa/ Cartaa gAographiquaa un coulaur Colourad ink (i.a. othar than blua or black)/ Encra da coulaur (i.a. autra qua blaua ou noiral Colourad plataa and/or illuatrationa/ Planchaa at/ou illuatrationa 9n coulaur Bound with othar matariai/ RaliA avac d'autraa documanta Tight binding may cauaa ahadowa or diatortion along intarior margin/ L« r« liura aarria paut cauaar da I'ombra ou da la diatoraion la long da la marga intiriaura Blank laavaa addad during raatoration may appaar within tha taxt. Whanavar poaaibla. thaaa hava baqn omittad from filming/ II aa paut qua cartainaa pagaa blanchaa ajoutiaa lora d'una raatau ration apparaiaaant dana la taxta. maia. loraqua cala itait poaaibla. caa pagaa n'ont paa «ti filmtoa. L'Inatitut a microfilm* la maillaur axampiaira qu'il lui a ixt poaaibla da aa procurar. Laa details da cat axampiaira qui sont paut-4tra uniquaa du point da vua bibliographiqua. qui pauvant modifier una imaga raproduita, ou qui pauvant axigar una modification dana la mithoda normala da filmaf « aont indiquAa ci-daaaoua. [~n Colourad pagaa/ D n D Pagaa da coulaur Pagaa damagad/ Pagaa andommagtea □ Pagaa raatorad and/or laminatad/ Pagas raatauriaa at/ou palliculAaa Pagaa diacolourod. stainad or foxad/ Pagaa dicoioriaa, tachatiaa ou piquiaa Pagaa datachad/ Pagaa dAtachias r^ Showthrough/ Tranaparanca n~| Quality of print variaa/ Qualit* inigala da I'impraaaion Includaa aupplamantary matariai/ Comprand du material auppl^mantaira Only adition availabia/ Saula Edition diaponibia Pagaa wholly or partially obacurad by errata alipa, tiaauaa. etc., hava been refilmed to enaura tha baat poaaibla image/ Laa pagaa totalament ou partiallement obacurciea par un fauillat d'errata, una pelure, etc., cnt Ata film*aa A nouveau da faqon i obtanir la maillaura imaga poaaibla. T» pfl of fii Oi bi th ai< Of fir ai( or Tl ah M( dil an bJ rig rai mi Additional commanta:/ Commantairea supplimentairaa; (Printed aphamara] [2] p. Paginatkin ii at f oiknki : 68 -89 p. Thia item la filmed at tha reduction ratio checked baiow/ Ce document eat film* au taux da rAduction indiqu* ci-deaaoua. 10X 14X 18X 22X 26X »X J 12X 18X aox a4x 28X 32X Th* copy fllm«d h«r« hat b««n raproducad thanka to tha ganaroaity of: ThiNowSeotia UflMathra LNirMry L'axamplaira Wmk f ut raproduit grica i la g4n4roait« da: Tha Nova Scotia UlMatfva Library Tha imagaa appaaring hara ara tha baat quality poaaibia conaidaring tha condition and lagibiiity of tha original copy and in kaaping with tha filming contract apacificationa. Original copiaa in printad papar covara ara fifniad baginning with tha front covar and anding on tha laat paga with a printad or illuatratad impraa- aion. or tha back covar whan appropriata. All othar original copiaa ara filmad baginning on tha f irat paga with a printad or illuatratad impraa- aion, and anding on tha laat paga with a printad or illuatratad impraaaion. Tha laat racordad frama on aach microficha ahall contain tha aymbol — ^ (moaning "CON- TINUED"), or tha aymbol y (moaning "END"), whichavar appiiaa. Laa imagaa auhrantaa ont 6t4 roprodultaa avac la plua grand aoin, compta tanu da la condition at da to nattat* da I'axarrnlaira film4, at mi conformM avac laa conditlona du contrat da filmaga. Laa axamptairaa originaux dont to couvartura an papiar aat imprim4a aont film4a an commandant par la pramiar ptat at an tarminant aoH par to damlAra paga qui comporta una amprainta d'impraaaion ou d'iNuatration, aoit par to aacond ptot, aalon to caa. Toua laa autraa axamptolraa originaux aont filmte an eomman9ant par to pramlAra paga qui comporta una amprainta d'impraaaion ou dllluatration at an tarminant par to damlAra paga qui comporta una talto amprainta. Un daa aymbolaa auhranta apparattra aur to darnlAra imaga da chaqua microficha, aalon la caa: la aymboto —*> aignifto "A 8UIVRE", la aymboto ▼ aignifia "FIN". Mapa, plataa, charta, ate, may ba filmad at diffarant raduction rattoa. Thoaa too iarga to ba antiraly included in ona axpoaura ara filmad baginning in tha uppar toft hand corrmr, toft to right and top to bottom, aa many framaa aa raquirad. Tha following diagrama illuatrata tha method: Laa cartaa, ptonchaa, tablaaux, ate, pauvant 4tra filmto * daa taux da rMuction diff«ranta. Loraqua to documant aat trop grand pour Atra raproduit an un aaul clichi, 11 aat filmA A partir da I'angto aupAriaur gaucha, da gaucha A droita, at da haut an baa, it pranam la nombra d'imagaa nAcaaaaira. Laa diagrammaa auivanta illuatrant la mAthoda. 1 2 3 1 2 3 4 5 6 ^ IT <•/ [Prom the Proceedings op the American association for the Advancement OF Science, Vol. XXX, Cincinnati Meeting, August, 1881.] Coal Ddst as an Element of Danger in Mining; shown bt THE Explosion in the Albion Mines, Nov. 12, 1880. By H. C. HovEY, of New Haven, Conn. A preliminary glance at the history of the Albion Mines, in Nova Scotia, will aid us to understand the part played by coal dust in spreading and augmenting the explosion that destroyed those mines less than a year ago. The Main Seam is 37 feet 6 inches thick, and is highly bitumi- nous. It has been continuously worked since 1807. The earliest workings were abandoned in 1839, on account of a fire that burned so fiercely as to melt the chains used in raising the coal-tubs. A new opening, the Bj'e Pit, was worked till 1863, when a fire oc- curred from a shot lighting gas, and the pit had to be closed up. The Foster Pit was next opened ; but in 1869 spontaneous com- bustion of slack caused a fire which necessitated its abandonment. At length the Foord Pit was won out, and with its improved ma- chinery, was regarded as one of the best mining establishments in America. The ventilation was effected by a large Guibal fan, said to be capable of circulating 120,000 cubic feet of air per minute through the ramifications of the mine. Tlie drawing shaft is 1,000 feet deep, and the workings extend 1,800 yards to the north, and 1,700 yards to the south, the galleries varying from 9 to 15 feet in height, being driven in the upper part, tlie lower being left for later operations. Shortly before the accident referred to, I went entirely through the colliery, in company with Mr. Ktiwin Gilpin, Inspector of Mines, and we remarked the perfection of the ven- tilation, which was *hen maintained through tlie south-side at the average rate of 25,000 feet per minute, and expelled the deleterious gases from even the remotest bords. On the mornin! of the disaster the night watchman reported the mine to be free from gas, except in small and harmless quantities. From what source, then, originated the series of explosions that began, within an hour from the time this report of entire safety was made, and continued at intervals until the mine became a fur- nace, whose flames could be subdued only by emptying into its burning chambers the waters of the adjacent East River? Was there some sudden exudation of gas from the solid coal? Or was tins explosion due to the tiring of coal dust from the flame of a (G8) :4> f f I -V f I J IT i V I j-a COAL DUST; BT H. C. HO VET. 69 blast, an unsound safety-lamp, or even a match by wbich some unlucky workman, forgetful of the rule?, undertook to light his pipe? None of the forty-four men who witnessed the beginning of the catastrophe escaped to explain the mystery ; and those rescued from more distant galleries had but conjectures to offer. The workmen, on receiving assurance that the mine was free from gas, went down the drawing-shaft, took their safety-lamps at the lamp-cabin and went, a part of them into the north-side works, and the rest into the south-side dips, where they waited for their tools. At this moment, the explosion took place. It was first noticed at the fan-shaft, and a minute later at the drawing-shaft, having in one case travelled with and in the other against the ven- tilating current. Additional facts were gained, at the imminent risk of life, by Mr. Gilpin, and are as follows : The exploring party went as ftir as the after-damp would allow. The locality where the workmen were known to be was 1,200 yards south of the shaft, and the party went about 600 yards in that di- rection. It was evident to them that the flame had not reached so far, for no marks of fire were on the dead bodies found, nor was the splintered woodwork charred. Tiie walls looked as if swept by a broom, and were clear of timber. Volumes of dust lay on the floor, into which the party often sank to their knees. Clouds of finer particles were swept on into the north-side levels. At the lamp-cabin an open light had been kept burning for years, as it was considered safe, being within a few feet oi the bottom of the shaft. But here a secondary explosion took place, demolishing the cabin, fatally injuring the lamp-man, and burning tlie horses near by. The effect did not extend far into the nortli-side, and the men there were ignorant of tlie disaster, till warned by tlie overman to leave the pit. Secondary explosions, caused by generated, or extracted, gas, are usually near the primary one. But here is a case where the second was half a mile from the first, with an intervening space of a quarter of a mile known to be free from gas, because men were in it with lamps which gave no sign of its presence. The Ignition of these volumes of dust did not harm the shaft- ing, because it was wet, and the fiame was extinguished as soon as it touched the damp walls. Elsewhere this mine was a very dry one. [Salem Puess, January, 1882.]