TRACT 36 .
THE WHIRLING-MACHINE.
171
Hemisphere n° 3, with Weight at m = 28 dr = 1 oz 12 dr.
Plane Side Foremost.
Turns
Time
Gifts.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
o' 2 T’
• 47
1 6
• 24
• 42
2 0
• 18
• 36
• 54
3 124
• 304
• 48
4 5
• 00 1
2,
20
19
18
18
18
IS
18
18
18-i-
18
HI
17
n*
1
00
1
I
tt
1
f means
or 1*552 ft.
1
J
Convex Side Foremost.
Turns
Time
Diffs.
3
6
0' 59"
1 37
38
35
9
12
2 12
2 47
35
35
15
3 22
3
35
'l
1
114
f
> means
?T
2-349 ft.
1
)
Note , that the resistanceof the arm is still wanted tobe deducted from these re-sistances, and then to bereduced from the circum-ference of the barrel to thecentre of the hemisphere.
In these tables, the first column contains the number ofturns made by the arm ; the 2nd the corresponding timeselapsed from the beginning ; and the 3rd shows the differ-ences of those times, answerin'}- to the differences of the turnsin the first column.
May. 3, 1786.
Barometer 29-63 ; Thermometer 51.
13. Fitted on the arm the thin bit of lead only n° 3, of thesame weight with the largest hemisphere; and after sometime spent in levelling the instrument, (which was alwaysdone) suspended different small weights at the end of thethread, to discover which weight would give to the arm thesame velocities as it had on the day before, when the hemi-sphere was on. It was found that it required about 10 drams