322 Descnptlon rif an improved tlygrowcfcr. 



permitted, before I conclude, to say a few words on what 

 has fallen from the learned Professor, in the same number, 

 respecting the Stanhope system (p. -117) : and first I would 

 ask, How is Dr. Sitiith's system, or vhifunave, to be reduced 

 to a doitr.eave for use on the common instruments ? And if 

 this is not to be done, but the doctor's unmutikUcd system 

 to be used, surely it must be preferable \o the isotonic ? 



The test which we find proposed in tliis ])age, of the com- 

 parative correelness of different tempered systems, appears 

 to me useless, and incapable of anv decision : if the singer, 

 or violinist, is to make perfect chords with the notes which he 

 hears on the imperfect or tempered instrument, are they to be 

 miisons with the upper notes ? and with which of those notes, 

 if the piece is full ? or are they to be true conchords to the 

 bass? In either case, what result can he expected different, 

 from what might have been heard on the instrument itself, 

 without singing or fiddling to it? I cannot doubt but the 

 learned Professor would, on reconsideration, prefer examining 

 a table of the differences of the logarithms, and of the number 

 of beats per second, to any test of this kind. ^ And I remain 



Your obedient servant, 



12, Upper Crown-street, Westminster, JOHN f AREY. 



May ii; 1807. 



LTII. Description nf an imprnvcd Hi/grometer. By Lieic- 

 tenant Hknrv Katkr, of His Majesty's I2th Regiment. 



To the Editor of the Philosophical Magazine. 



Ts^'^' . . . ' . 



HE following paper was forwarded, some time smce, to 



the Asiatic Society at Calcutta, and will probably appear in 



the next volume of their Research c's ; but as the hygrometer 



ofwhich.it contains a description is at present made by Mr. 



Thomas Jone;;, of No. I'i4, Mount-street, Berkley-square, 



I conceive some account of its construction, and manner of 



ujing it, rnay not be unacceptable to your readers. 



I am, sir, your obedient servant, 



London, IIkNUY KaTI-R. 



.Vi;.y H, 1H07. 



The 



