208

THE LIFE OF

" count of Epidemical Diseases , of Blasts, Mill-Dews, and other Accidents," belonging to Grain, Cattle, Fish, Fowl, and Infects. And because thecc Difficulty of a constant Observation of the Air, by Night and Day, seem’d* In the M« “ invincible, he therefore devised a Clock * to be annex’d to a Weather-forum of the Cock, which niov'd a Bundle cover'd with Paper, upon which the Clocli£°^Grew’j ’‘ c mov ’d a black Lead Pencil, so that the Observer by the Traces of theCatalogue , p-“ Pencil on the Paper, might certainly conclude, what Winds had blown357 ‘ " in his Absence for twelve Hours space : After a like Manner he con-

" triv’d a thermometer to be its own Regiser: And because the usual“ thermometers were not sound to give a true Measure of the Extension“ of the Air, by Reason that the accidental Gravity of the Liquor, as" lay higher or lower in the Glass, weigh’d unequally on the Air, and gave" it a farther Contraction or Extension, over and above that which was pro-" duced by Heat and Cold 5 therefore he invented a circular thermometer“ in which the Liquor occasions no Fallacy, but remains always in one Heigf 1" moving the whole Instrument like a Wheel on its Axis.

[In an Improvement of his Invention of the Weather-Wheel, (the onlytrue Way to measure Expansions of the Air) he contriv’d the Instrument tobe more firmly made, by causing the circular Pipes (which cannot be truelfblown in Glass) to be form’d of Brass, by those who make Trumpets al>oSack-butts, who wiredraw their Pipes through a Hole to equal them, at>othen filling them with melted Lead, turn them round into what Flexure 5they please : The Inside of the Pipe he varnistsd with China Varnijh , to pre"serve it from the Quicksilver, and the Glass fix’d to it, with Varnilh ; whichis the best Cement in the World, for thus the Chinese fix Glass and Mother ofPearl in their Works.]

To his Invention of the IVeather Clock, other Motions were afterward 5

added by ML Robert Hook, Professor of Geometry in Grejham- College.

' ' It hath six or seven Motions; first a Pendulum Clock, which goes with three

quarters of a ioo Ib. Weight, and moves the greatest Part of the Work withthis, a Barometer, a thermometer, a Rain-Meafure ; such an one as is next de"ferib’d ; a Weather-Cock ; to which subserves a Piece of Wheel-Work analo"gous to a Way-Wister • and a Hygrofcope ; each of which have their R'

gister, and the Weather-Cock hath two ; one for the Points, the other f° l

the Strength of the Wind. All working upon a Paper falling ost of a RgHoPwhich the Clock also turns.

Mr. Hook’s Proposal for augmenting the We other-Clock, was first offer’d h/him to the Royal-Society in the Year 1664, upon the Description of 0^made by Sir Christopher Wren. [Wallers Life of Hook, page XL]

Dr. riot’s not. The Instrument call d the. thermometer, tho’ of very ancient Inventic* 1 '

1 Hist. of Ox- there having been one of them found by Robert de Flublibus graphically d e "ford,/. 229. ii neate( j j n a MS. of five hundred Years Antiquity at least ; yet it has stillsceiv’d other useful Advancements from that curious Artist Sir Ch. Wren,the Invention of the circular thermometer.

4 h the Mu- “ He contriv’d an J Instrument to measure the Quantities of Rain ^Jst um , th . e . " Llls in any Space of Time, on any Piece of Ground, as suppose onD*. GrewV’“ Acre in one Year; this, as soon as it is full, will pour out itself, and *Catalogue, p. " the \ ear's End discover how much Rain has fallen on such a Space of La p '" or other hard Superficies, in order to the theory of Vapours, Rivers,

" &C.” [A Triangular Tin Vessel hanging in a Frame, as a Bell, withAngle lowermost. From whence one Side rises up perpendicular, the otl^lloaped ; whereby the Water, as it fills, spreads only on one Side from 1:1Centre, till at length it fills and empties itself. Which being done,leaden Poise on the other Side, immediately pulls it back to sill again.] ^ ^