348 CouLroversy respecting Safe-latnps. 



aiburiium of such oak trees contained at this period; and I found 

 that 1000 parts lost by drying only 371 parts: which is not 

 more than the vveigiit of the water that the cellular substance 

 appears capable of containing, entirely iuclependent of the tubes. 

 That the tubes, nevertheless, are not alwavs eaiptv, but that 

 they act at other periods of the year as reservoirs for the sap, I 

 have piven an opinion in a former conmuniication ; and I am 

 now in possession of facts which prove them to jjcrform this 

 Oiiicc, even in the heart wood, to a much greater extent than 

 I had ever at any former period suspected ; and which incline 

 ine to believe, that the dinabihty of the heart wood, as we'i rs 

 of the alljurnum of the oak, will be found to depend to a great 

 extent upon the period in which the tree is felled : but I propose 

 to make my observations upon these points the subject of a fu- 

 ture communication. 



I am^ mv dear sir^ Sec. 



T. A. Knigkt. 



LXX. Controversy respecting Safety-lamps. 



Xjast month, but too late for insertion in our October number, 

 v.'c received from a respectable corre^^jjondent at Newcastle se- 

 veral articles which have a|)peared in the Newcastle Courant, 

 claiming for Mr. Stephenson priority of invention of the safe- 

 la.inp. — When the invention u'a^ first announced, we stated our 

 opinion that Mr, Stephenson and Sir Humiihry Davy made 

 each their discoverv independent of each other. Mr. Stephen- 

 -son's friends, on the contrary, have expressed an opinion that 

 Sir Humphry's was derived from Mr. Stephenson's; and in sup- 

 port of their opinion tlie dates of his experiments have been 

 brought forward by himself. Sir H. Davy's friends, resting also 

 on dates, have shown that Sir H. was prior. Of course, if dates 

 are to be taken as evidence, not merely of priority of invention, 

 but as proof that the one who was latest must have borrowed, it 

 will follow that Mr. .Stephenson's lamp was derived from Sir 

 Humphry's. — The following are the articles which have appeared 

 on this subject in the newspaper to which we have alluded. 



From tite Newcastle Courant of the \dtli of October. 



I trust the public, and gentlemen of the coal trade in par- 

 ticular, will excuse mv refpiesting their attention to a letter from 

 Robert William Brandling, esq. to the meeting summoned for 

 the purpose of voting a piece of plate to Sir Himiphry Davy, 

 and to a resolution which he moved at a subsequent meeting, 

 and which was seconded by Arthur Mowbray, esq. Whether or 



not 



