On ventilating Coal-pits. 59 



getting rid of the carbonic acid gas (choke damp), have been laid 

 before the Society for Preventing Accidents in Mines by Lord 

 Percy, and the Roval Society of Edinburgh, by Mr. Neili, Secre- 

 tary to the Werneiian Natural Historv Society. My remarks 

 were before the public in August last, and three months ere thi.^ 

 in the bands of my printer : I had also comnuuiicated niy sen- 

 timents hereon even long before, to my friend J. C. Gotcn, esq. 

 banker, Kettering. Far from imderrating the value of Sir H. 

 Daw's lamp, 1 think it deserves instant adoption, and to be 

 continually used. These lamps may go together: the one is 

 more convenient for general purposes, tlie other will act in cases 

 where its fellow is of no use. Sir H. Davy's exertions in the cause 

 of humanity deserve the eternal gratitude ot that species ot which 

 he is an honour. I confess I see no force in the objections oi Dr. • 

 Thomson to Sir H's safe lamp. . 



« If vou will allow me, I shall in your ne:;t number give such 

 cautions in the employment of charcoal, and m the occurreme 

 of choke damp in cellars, wells, &c. and the means oi subdumii- 

 their effects, as may be useful. ' ,»» » 



" Cari.s. 1.1. 8 1316 J. Murray." 



On'^this day,' reperusing the letter in the Monthly Magazine 

 %vhich Mr. M'. thus harshly and unfairly commented on, and also 

 an earlier letter of mine in the same work, inserted also in your 

 xlvth volume, p. 436 and contrasting these with the numerous 

 letters, papers, and essays which have since appeared on the 

 subject of inflammable gases in coal pits, I beg to say, that 1 

 do not observe a single fact or point of my arguments therein, 

 which has yet been materially shaken, by any thing which has 

 since transpired or been adva'nced. . Indeed, Mr. M. alone seems 

 to have had tiie hardihood, to attack either the matter or the 

 manner of my communications ; and in what way and manner he 

 (who now affects moderation) did this, your readers will see above 

 1„ arguing (Monthly Mag. Vol. xh. p. 3:].) on the chiet and 

 peculiar defects of the Newcastle system of Collierying, viz. the 

 vastly too sreatly extended IVorks to he veniilntcd by one up-cast 

 Shaft, 1 assumed only, with Mr. Bu<ldlc, that the " run of the 

 air '' or length of laterally air-tight gallery, winch required to 

 be'constantiv maintained, " or imminent danoer ensnes, some- 

 times exceeds thirty miles ! ; but on making i.u,u.nes, last summer, 

 us I passed through, and made a short stay at Newcastle, I was 

 then very credii.lv informed, that I had very great y under-rated 

 the extent of i\K'\h,ef cmise, which had occasioned so much fuss 

 about safety-lamps ; for that forty, fifty, sixty, and even ninety 

 ,niles of such air-courses were, or had ately been ""enipted . 

 be maintained, between a down-cast and an up-ca,st shaft . ; an, 

 jhat in various parts of this vast single magazine of combustible 



