TRACT 36.
THE WHIRLING-MACHINE.
183
greater than, those of the former day; and consequently,that the resistance on the convex surface of the cone, isnearly equal to, but rather greater than, that on the globeor hemisphere, the diameters being equal, but the height ofthe cone being a little more than double the height of thehemisphere.
34. The following experiments were next made with thebase of the cone foremost.
Wt.
Time
Wt.
Time
; Wt.
Time
Wt.
Time
OZ
sec.
OZ
sec.
OZ ■
sec.
OZ
sec.
12
4-95
24
3-tO
43
2-37
72
1-93
16
4-25
30
3-05
56
2'20
80
1-85
20
3-11
40
2-60
64
2-02
100
1-65
These times are rather higher than those of the cylinder.But the cone was rather the heavier, and their after partsdifferent.
35. June 30, 1786.
Barom. 30'02 ; Therm. 61, at 9 A. M.
Put on the smaller hemisphere, the flat side to go fore-most, in order to compare with the large one, to try if theresistance be as the surface, when the axis or radius is thesame. The flat surface of this hemisphere is equal to | of asquare foot, but that of the large one ■§-, their proportion be-ing as 16 to 9, the radius of the small one’s path 52"42, of thelarge one 53-34 ; the compound ratio of the surface andpath or radius, being 16 X 53 34 to 52'42 x 9, viz, 38 to 21nearly, or as 11 to 6, but not quite so near.—Note that 6 drjust gave motion to the machine.
1
21-80
7
4-67
20
2-65
56
1-57
2
10-82
8
4-35
24
2-45
64
1-45
3
T70
10
3-90
28
2-25
72
1-40
4
6-47
12
3-50
32
2-10
80
1-82
5
5-67
14
3-25
40
1-82
■
6
5-15
16
3-00
48
1-67
1