ay 
342 Genet’s Memorial. 
Comparative Table of Hydrostatic Forces, 
Cubic foot of 
‘ atmospheric air. Fresh water. Salt water. 
108 
10 1000 1080 
20 2000 2160 
0 3240 
40 4000 4320 
50 5000 5400 
60 6000 6480 
= 70 7000 7560 
80 . 8000 8640 
90 9000 9720 
100 10,000 10,800 
200 20,000 21,600 
300 30,000 — 32,400 
400 40,000 43,200 
a 50,000 54,000 
— 60,000 64,800 
700 70,000 75,600 
800 80,000 86,400 
900 90,000 97,200 
1000 100,000 108,200 
power is to be applied, Ist, to raise or lower, verti- 
cally, canal boats to a high altitude ;.2d, to al 
‘boats or steam-boats, arrested in their course se breaches, 
“Shallow water, or deposits of mud and other substances; 
, to raise vessels stranded, foul anchors, snags, planters, &c- 
and to raise v, ertically heavy weights on the water and on 
Tand ; 4th, to prevent ships and vessels from s sinking 
men from drowning. [It is for these important objects that 
a vertical ele- 
rizontal, and 
5 t too, as the followin dieqeane can better ex- 
' to an attentive reader S 
_ Hydrostatic Eleseties (Vid place 2) 
It is an indi ispensable 1 quisite, that water can be procur- 
ed from any convenient place, above the level of the water 
» When the most perpendic cular part of a hill is to be 
Straitened vertically, and to resist any presse, this A 
also strengthened by y retaining walls necessary : 
