Letter 1427

[fol. 297] Sr Upmr Feb: 21 1708/9 I have lately recd Dr Newtons Answer from Flo- rence wch I have send you, wherein tou will find his willingness to accept the Societies favr of being chosen into their Number. And by the speediness of his Ansr to that past of my Lr, & his passing over other material matters I have sent about, I imagine that the sooner the favour can be done, the more acceptable it will be. The Papers which he mentions as sent wth his Lr, I shall bring to you when I can get next to London; which I intend as soon as I can. You will find by the enclosed, That in Italy the cold hath this winter been very intense, as well as in England. If by Twelf-Day his excellencie means our Jan: 6th my Thermometer was then very low. But if he means Jan: 6 N.S (as probably he doth) I find the Italian Cold preceded ours 2 or 3 days. For the days before Jan 6: N.S were warm, yt day it began to freeze; the two next days were sharper frost, wth snow: but the Night after the fol- lowing day, viz the Night between Dec: 29 & 30 O.S my Themr was much lower than ever it was since I began my Observations therewith in ye year 1698. Ans as his Excellence saith they wanted but half a Degree of the extremity in Italy on Dec: 26 (as I imagine their Twelf-Day was) so at 7 of clock in the morning of Dec: 30 my Thermometer descended with- in to of an inch of the very point to wch I formerly (for a tryal) forced my Spirits down with artificial Freezing wth Snow & Salt. I have been informed yt your Thermr in Town have this winter been lower than in the Great Frost, altho not on the same day yt mine was. The reason of wch I conceive to be either from the different temperature of your City, & our Countrey air: or rather from the different Freezing within & without doors; my Thermomr being allways kept without doors, in the open air; & your Glasses in London yt I have had any informations from, being kept within doors. Speaking of Artificial Freezing, give me leave to suggest one curiosity about it, & that is That after you have made the Spirits contract as much as is possible wth snow and salt, you may force them yet lower, & that somewhat considerably, by pouring upon your Frigorifick Mixture Spir. of Wine. I know other have observed yt snow & So: V will together freeze; but I do not know whether they have observed yt it will encrease the strength of Snow & Salt, or whether it will do more wth Snow or Ice than Salt can, Now the cold goeth off, & gives a relaxation to my Fingers & Ink, I being to think Of drawing up a Table of Dr Scheuchzers, Dr Tillies & my own Observations for the Socities Use, being highly obliged to be ever Their & Your most humble servant Wm Derham