last I arrivj^d at the conclusion that a metallic tissue, however 

 mi'Miiti^, of Mfch^the apettv^res flljed in6re sfi^^g^sfe 

 tfe'e Vtoolirt^ siirtad'eV ,^0 %k '^d^be permealJl^ tb' aft: aildi liMit;^ 



n6,mber hf surfaces. . . 



y^w ' jJly 'firk safety lamps co'iistWtiifed oTif'tfie^e pffidples, gSV^^ 

 ifght 'irt' ex'plosive mixtures containing 4 greUt eitess of air^" 

 l!)\lit liecariip extinguished in explosive' mij^tures in ;v<rftich the fti^ij 

 daWi^'^^a's itt siiffici'ent quantity to absorb, tljef'-wfiole^'bfthfe' 

 a^gfe^ of the air, bo that such mixtures never burnt fcontitiu-i.' 

 ously at the air-fe^d6rs, which 'in limps of this tohstHifcttdh; 



6cvlnt^/" 



^'i^^fiti^%ahy' other attempts to boi^sti-uct a safety. laflip'whi^If^ 

 ^'6iild larisrv^ei' in all- mijitures of fire-dariip, Sir H.'-DaTy 'hit' 

 i^pon the simple and effectual expedient . of surtounding the^ 

 liy;^';e^tfre|y ^rth Vlt^ ' giiiz? ' "' and mating 1*6; sertie iissie 

 fbeatfe'flariT^'Wi&^irkitr emit light.*' ■ -'' -/'' ' --' -"^^ 

 ; " In plunging a light surrounded by a cylindet df iinfe'^wef' 

 ^kuze Into an explosive rtiixture, 1 saw tlife-'A^Iiblis cylihd^r'' 

 ^ecome t|^uietly and giadually filled Avith flaitie ; the' Upper pait^ 

 ctf itsoon appeared red hot, yet 7io explosion was produced."''-^ 



"^-SlrHumphry Bavy next proceeded to put the efficacy of this? 

 admirable invention, which, whilst it " excluded the necessity^ 

 of using glass, or any fusible or brittle substance in the lamp, 

 rii^t- only deprived the fire-damp of it'^ explosive Jtdwieir^j' 

 but 'rendered it an useful Ught; " to the most severe trials he- 

 could devise, in order to be absolutely certaia of jts safety 

 under all possible cirbiimstandes ; and he found **\that^"ii'6n^ 

 wire gauze, composed 6f wires from one-foitieth to one-sixtiet'h^ 

 of an inch in diameter, and containing twenty-eight wirtes,' 

 or 784 apertures to the inch, was safe " in the mo^t ex'plos?jrt^ 

 atmospheres composed of the gak produced by the distillation 

 of coal (which always dontairis olefiarit gas, an explosive mix-' 

 ture of which with "atmospheric air inflames by tpntiact*ith^". 

 rfed h()t Irbn or charcoal) and common air. ' ' •'" ■" .- ^" '';■' '" 



- This mode of structure was consequentiy'ftadiited ;-ah|d''Jrt| 

 January; 1816, the safety lamps Were introduced in the coal 

 mines; and have ever since been in general use." i ''1 .■•' v '-"^ "^' 

 fn 1817, ,irt consequence of his, researches <Jri'tHe?fajir'^AWf**P 

 flatii'e, Sir H4raphry Davy made an important praclieal Addi-j 

 tj'btf ''fo ^-tHii '!athp,' founded entirely" '9n at' rttW principle. He 

 ^sp'endedVlftrie'bige of fine ^hitm ^ii-e - witllih th^' lAM^,' 

 by Wans of Which the lamp yi^ds ^ light- ih atifto^pheWs^'^teoi 

 n^ttc^ ,c(?^at;^j?ipftt94,,with,,4r,e;,d^o>f ,t9, be expl9^iw vn",^^°>^ 

 c<m>binatu)9:beiBg^e^e€teid^bw'|ti)e} ma%mupm\ua^ikfi^if^t»f^ itpifti 



