Complete Extant Works of Hero of Alexandria, Vol. 2 (1900) - Page 13

		Page
	triangle on the supports under the vertices	195
40 (40).	Center of gravity of a triangle to which known weights are attached at its vertices	197
41 (41).	Center of gravity of a polygon with the same condition	197


1 (1).	Aids for moving loads on planes	201
2 (2).	Lifting machine with one mast	203
3 (3).	Lifting machine with two masts	207
4 (4).	Lifting machine with three masts	208
5 (5).	Lifting machine with four masts	209
6 (6).	The "hanger," by means of which the load hangs on the pulley	211
7 (7).	The "crabs" A term for specialized grappling hooks or clamps., which serve the same purpose	213
8 (8).	Three iron pegs embedded in the load for hanging the same	215
9 (9).	The mountain ropeway for the transport of stone blocks	219
10 (10).	Similar procedure for lifting columns	223
11 (11).	Transport of large loads by water	223
12 (12).	Straightening leaning walls	225
13 (13).	First lever press	227
14 (14).	Hanging the stone on the press lever	229
15 (15).	Second lever press	229
16 (16).	Manufacture of the galeagra a wooden crate or cage used for lifting from slats	239
17 (17).	The plate galeagra	239
18 (18).	Difference between lever press and screw press	241
19 (19).	The press with two screws	241
20 (20).	The press with one screw	249
21 (21).	Manufacture of the female screw The nut or threaded housing.	249

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