hibebantur, quam aliis recentioribus plurimis, medio- 
cris quidem longitudinis, quarum maximae feniiirent 
pedis non excedebant, led gracilioribus & vivacibus, 
animadvertebamus, quod mirum^declinationem acus a 
priftina nec in uno minuto difcrepare, fed in quavis me- 
I'idiana exade cum priori convenire, ad Occaf. fcili- 
cet 5V An autem intcrea temporis ulterius procefle- 
rity ut nunc in fitu retrogrado ejus deviatio deprehenfa 
fuerit, quod cferte cafu evenifle potuiftet, non liquct,cum 
nec temere iftud ftatuere, quin in earn fententiam^kquod 
ftationarius (procul dubio cireularis motus) in eodem 
puii<ad ^etmanfe^it, ^(&iiius abife^ velimus^ 
- r - J i:: : ,obom nij^Iuv mh1S:^ .^udiiu 
Ita t>. Mmmartm i^tictv^^xt ad amitum fuum Jndream 
Arnaldtm , qui iflfhseC ^gi(^ Societati Londinenji^ Fau*. 
rrici plJm itye, tuben^ metiiip^u^ tranfmittit. 
y;-,?^?'- -h; •-uv.r:;,:-h , 
1 Wm '^ conterning Dr 
Papin'jp mw Water-Enginc. 
Sin, 
THE other day J upon reading in the TrmifaUxonfy 
a defcriptionx)f the effect s o£ 2l Water-Engin, in- 
Tented by D'^ Papin^ and propounded as a Probkme to 
find out the contrivance, there came into my mind the 
follov^ring thought. I do not think it is the famcA^ith his, 
nor fo good, but luch as it is I fend you, becaufe Variety 
offancicsgim hints m'ahy tim^s to better new inven- 
cions. 
Tab. I. Fig, liAB D E £i%mfk% a cylindrical Veffel, 
dofed 
