(440) 
long Wiie-ftaple B, in the Ball A, and a fpringing wire C, with a 
bended end F, and into the faid Staple, prefs in with your fingers 
the fpringing Wire on the bended end : and on it hang the weight 
D, by its hookE, and fo let Globe and all fink gently into the 
Water, in the pofture reprefented in tht (^id Figure ^ to the bot- 
tom 5 where the weight D touching firft , is thereby ftopt > but 
the Ball, h6ngby the Impetus it acquired in defcending , carried 
downwards a little after the weight isftopc, fuffers the fpringing 
•Wire to fly back p and thereby fets itfelf at liberty to re-afcend. 
And by obferving ihe time of the BalFsftay under Water f which 
may be done by a Watch ^ having Minutes and Seconds 5 or by a 
good Minttte- GUfs'^ or beftof all , by z Pendulum^ vibrating Se- 
conds V the which muft be three foot, three inches, and one fifth of 
an inch long, fviz.. between the middle of the Bullet and the up- 
per end of the Thred , where it is faftned^or held when it vibrates.) 
Yoii may by this way 5 with the help of fome Tables^ come to 
know any depth of the Sea, 
Note 5 That care muft be had of proportioning the weight and 
fliapeof the Z^'^^, to the bulk, weight, andfigure of thecMej 
after fuch a manner , as upon experience ffiall befound moKcon- 
vement. . - . •r^jU^u^.V' 
In fome of the Trials already made with ^this Inftrument , the 
Globe being of Maple-mod^ well covered with Pitch, to hinder 
foaking in , was 5 II inchesin Diameter , and weighed 2lpounds 
the Lnd, of 4^ poundsweight, was of a C^?;?/^^/ ( but is'now u- 
^fedof a Giohoiis') 'Figure 1 1 inches long^ with the fharper end down- 
wards , I at the bottom in Diameter^ And in thofe Experiments 
madeintlie Thames ^ in the depth of 19 foot water, there paf- 
fed between the Imraerfion and Emerlion of the Globe, 6 Se- 
conds of an hour^ and in the depth of 10 foot water ^ there pat 
fed 3 1 Seconds, orxhereabouts.: Prommanyof whichkindof Ex- 
periments, it will lik:ely riot be harAto find out a method to calcu- 
l:ue , what depth is to be concluded from any time of the like 
Globes ftay under water : As for inftance , if in the depth of 20 fa- 
thom p meafured by the Line , the Globe ftay under water ly S e- 
condsv then if the Ball ftay 700 Seconds, the depth of the Sea is 
5 3 j fathom and 2 foot , if the Ball.be found to move equal Ipaces 
,in equal time, 
1« 
