170

EXPERIMENTS WITH

TRACT 36.

May 2, 1786.

Barometer 30-05; Thermometer 51.

12. Measured from the axis of the cylinder to the centreof each hemisphere, when fitted on the arm, and found themas below, on the line of radii; thence are found the follow-ing lines of circumferences, &c.

N° 1.

N° 2.

N* 3.

inc.

inc.

inc.

Radii

5242

52-74

53-34

Diams. .

104-84

105-48

106-68

C'ircum.

329-36

331-38

335-14

Ditto feet .

27-47

27-62

27-93

Ratio of radii

50-2

‘ 50-5

51-1

The last line being the ratio of each of those radii to thatof the barrel and thread l - 014, or the former divided by thelatter.

The hemisphere n° 3 was then fitted on, and actuated by asmall weight of only l^oz, or loz 12dr, that is l|oz sus-pended at the end m of the thread ; opposing first the roundside to the air, and then the flat side; when the number ofrounds, and corresponding times, were observed as follows,both now, and in all the other experiments, by stop-watches,and a peculiar clock made for the purpose.