Hooke Folio
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© The Royal Society

29

a stringy plant growing at the bottom of a pond giuen by Sr. R moray) this with the glasse of cantha
redes were Deliuerd to mr Hooke for the Repsitory. the Opr: produced the steel case for gunpowder
Opend whereof some being taken out & held ouer the fire in a peice of Paper gaue noe
Report at all but flamed away wthout any noyse it being found calcined in the cauity.
and turned into an alcaly as growing moyst in the air the nitrous part hauing been de
stroyed by some vent or other wthout cracking the case made extraordinary strong.
orderd tht the like Expt. be repeated both wth Prince Ruperts &. the Fuliminating powder
at the next meeting (calcining antimony by the sun) mr. southwell of Pilchard fishing)
mr Euelyn said that one mr. smith hath published a book about herring fishing shewing all that
is materiall in that practise) Haak Of Ling). There were made seuerall expt. of Breaking
wood. 1. a peice of fir 1/2 inch diam: 3 inch long .at wch Distance the weight hung. broke in the
plaine of the graine horizontally. wth 66 3/4 pounds. whereof 15ll troy vertically wth 2 pound
more. 2. fir of 1/4 inch Diam: & 1 1/2 inch long broke vertically wth 20 pound and horizon
tally wth. 19ll. 3 Elm of 1/2 inch diam & 3 inch long broke horizontally wth 47. vertically
wth. 23l. 4ly. Elm 1/4 inch diam: & 1 1/2 inch long broke. horizontally wth 12 vertically wth
10ll. (expt for next Day. those of the celerity of falling bodys. & of the Fulm: powder & P Ruperts
powder in steel cylinder. 3 of breaking more kinds of wood. mr. Hook was also ordered
to think of one or two more expts. more for that time.
Iuly. 6. 1664. An expt. was made to Measure the velocity of a sounding string
or to Determine how quick the vibrations are in a certaine space of time
There was taken a brasse wire of 136 foot long And of 1/32 of an inch diameter &
weighing this string extended by a weight by 3 . . . 3 3/4 pounds + 1 pound 10 ounces
and being made to vibrate in the middle its vibrations were found to be half seconds
then being stoppd in the middle & the half of that made to vibrate in the middle
was found twice as swift. or to vibrate quarter seconds. whence the Length & Vibra
tions appeard Reciprocall & by measuring how much the line did bend -
below a streight Line it was found that the distance was equall to the Length
of a pendulum vibrating equall times wth. the string. Reckning that Length
from /the streight line to/ the center of grauity of the parabolicall string. then further stopping the
wire wthin one foot of the end & striking that short part it was ghessed to
giue a note of G. Sol Re vt. which is to be explained by a pipe next
Day. soe that it seems that the velocity of the vibrations of a string tuned to G sol re vt
is 272 times in a second.
The expt. to shew how quicke the vibrations must be to giue a certaine sound; being
made, it was tryed wth. the same string wth. what velocity a sound is propagation
and found that there is noe perceptible Interuall of time between the stroke of
one end of the string, and the hearing of the sound at the other end. It was
orderd that the string should be Lengthned for the prosecuting this Experimt.
(capn. taylor of the plant to kill Rattle snakes.) Thunderstone from Pendennis)
Expts. of breaking wood prosecuted. A peice of Oak 1/2 inch Diam. 3 inch long broke horizontally wth 48ll
vertically wth 46ll. a like peice of Ash horizontally wth. 77. vertically wth. 75. Ash 1/4 inch Dia
meter & 1 1/2 inch long. horizontally wth 19ll. vertically with 23ll. Oak of the same dimensions
horizontally wth. 15ll. vertically wth. 12. orderd to try the best part of oak also to try Dr
Godderds comparatiue way of breaking fir & Elm both direct & transverse graine
Capn taylor knew a french man could harden steel soe as not to rust) black heauy oak in the riuer Ex
Hatfield chase lignem fossile from a deluge) query Dugdale of dreyning the fenns.
mr. Hooke being called vpon to giue an account of the flyes found aliue in the glasse wth the dead Cantharides
said that hauing looked vpon them with a microscope he found them not young cantharides but como flyes
(viper powder after 6 months full of insects) myrrhe a preseruatiue against those wormes) flesh in a glasse coue
red wth. flanell bred noe wormes) The Expt. of common powder in the steel case was tryd in a strong
fire, but noe report heard but a Little hissing nor any crack found in the vessell. mr. Hook was to
bring some of his fulminating powder to be tryd in the steel case next Day. (the blood of pestilentiall
persons verminous - also the stomacks.