386 *Mr. Nicholfons Bejcription of a new Tnjirument 



"P' Jl the fuburbs of St. James's, Harp-ftreet, 

 " and even the ftreet of Tournon, ftand upon 

 *' the ancient quarries; and pillars have been 

 " ereded to fupport the weight of the houfes. 

 ** What a fubjeifl for refledions, in confidering 

 ** this great city formed, and fupported by 

 " means abfolutely contrary ! Thefc towers, 

 " thefe fteeples, the arched roofs of thefe temples 

 *' are fo many figns to tell the eye, that what 

 " we now fee in the air, is wanting under our 

 " feet." 



ji Description ef a New Instrument /or ?77^^- 

 Jiiring the Specific Gravity of Bodies. By 

 Mr. WiLLiAA^ Nicholson, in a Letter to 

 Mr. J. H. Magellan, F. R. S. Reg, Acad. 

 Petropol. ^ Paris. Correfp. &c. Read May 4, 

 1785. 



DEAR SIR, 



A CCORDING to my promife, I tranfmit to 

 you an account of the Inftrument I have 

 conftrufted for the eafy and exadl finding the 

 fpecific gravities of bodies. It appears to me to 

 be as perfe6t, as the nature of a floating inftru- 

 ment of this kind will admit of j and, for that 

 reafon, I prefume it will not be impertinent to 



mention 



