[ 94 j 



XXIII. On the pretended Priority of Mr. Stevenson's Safe- 

 lamp. By W. P. Knight, Esq. 



To Mr. Tilloch. 



Sir, — In my letter written to you last month, on the very 

 absurd claim advanced by Mr. Brandling, I stated it as my opi- 

 nion, that with respect to dates so near each other as those 

 q.'oted by Mr. Hodgson and Mr. Brandling, it was difficult to 

 draw any inference as to priority. In perusing, however, the 

 evidence with more attention, I feel it necessary to alter my opi- 

 nion. I had turned over the leaves of Dr. Thomas Thomson's 

 Journal, and in his account of the Roval Society for tiie last 

 year, I found in the notice of Sir H. Davy's papers no mention 

 made of either tubes or sa*"e apertures. On mentioning this to a 

 Fellaw of the Royal Society who was present when these papers 

 were read, he informed me that nothing could be more inac- 

 curate than Dr. Thomson's account. 



That in the first paper, read Nov, 9, it was distinctly stated 

 that explosion from fire-damp would not pass through small 

 tubes, and that small apertures were insisted u{)on in the safe- 

 lamp ; and that the great object of the second paper, read Nov. 

 16, was to enforce the use of tubes or safe apertures. The same 

 gentleman mentioned that he had seen a lamp fed with air by 

 four safe tubes in Sir Joseph Banks's library, in the middle of 

 November. On referring back to the Philosophical Magazine, 

 I find safe apertures and tubes distinctly mentioned as forming 

 leading circumstances in Sir H. Davy's papers. 



Nov/ the Rev. John Hodgson states, that he publicly com- 

 municated to various persons Sir H. Davy's discovery, that ex- 

 plosions from fire-damp would not pass through tubes of small 

 diameter, on Nov. 2d and 6th, that Sir H. Davy had made a 

 safe-lamp, and that this was mentioned to one of Mr. George 

 Stevenson's employers ; yet Mr. Stevenson shows no lamp with 

 small tubes till Nov. 21. Before this time he had made his ex- 

 periments with a tube and a slider. Will any person believe that 

 Mr. G. Stevenson did not endeavour to profit by what he had 

 heard Sir H. Davy had done ? Besides, if he had an independent 

 claim, why was It not made at this time ? When Mr. G. Ste- 

 venson's third lamp witli holes was brought forward Dec. 5th ; 

 this was stated to be the safe-lamp* that he had made before 

 Sir H. Davy's researches were published. But I must conclude 

 60 evident a case. 



Can Mr. W. Brandling be serious, or is he not attacking ifO" 



* SeePlii!. Mag. for Deccmboi 1816. 



wically 



