PHILOSOPHICAL WRITINGS OF THE LATE DB. DALTON. 13 



butions are equally meritorious and interesting^. His name is 

 appended to sixteen out of the seventeen questions proposed 

 for solution, and as most of them are of a difficult character, 

 we may safely infer that even at this period he had few 

 superiors among his contemporaries in mathematics and 

 natural philosophy. His ability in pure geometry and in the 

 discussion of loci appear very conspicuously in the solutions 

 furnished by him to questions 7 and 15 in this Diary, and in 

 several succeeding numbers we shall find him equally con- 

 versant with some of the most difficult branches of dynamical 

 inquiry. Question 10, in the selection for this year, is the 

 celebrated question respecting the exciseman's staff,* which 

 led to an interesting controversy between Mr. Wildbore and 

 Mr. James Wolfenden, of HoUinwood, near Manchester. 

 Mr. Dalton, in common with other correspondents to the 

 Diary, had solved the question on the supposition that the 

 staff exerted no pressure on the edge of the vessel ; but this 

 supposition was proved by Mr. Wolfenden, in the Mathema^ 

 tical Companion, to be incorrect, and the freedom of his 

 criticisms led Mr. Wildbore to combat several of his con- 

 clusions, but without success. More recently the discussion 

 has been revived in the pages of the Mechanics* Magazine^ 

 where the able investigations of Tebay, Workman, and Inda- 

 gator have apparently set the question at rest, and confirmed 

 the general accuracy of Mr. Wolfenden*s results. The editor 

 of the Gentleman*s Diary evidently considered his scientific 

 reputation at stake, and by means of his correspondents con- 



• Question 609. By Mr. John Fletcher. " Seeing an exciseman's staff io 

 the form of a cylinder, three-fourths of an inch in diameter and 36 inches long, 

 immersed in a vessel of beer at one end, and the other resting ui>on the edge of 

 the vessel, 8 inches above the liquor, I observed 13 inches along the staff to be 

 dry ;— required the weight of the staff, the specific gravity of the beer being sup- 

 posed to be known." 



