4.  The degrees refer to the centigrade thermometer.

TABLE C.
 
Approximate Height. 15° 40° 55°
200 1.2 1.0 0.6 0.4
400 2.4 2.2 1.4 0.8
600 3.4 3.2 2.0 1.2
800 4.5 4.3 2.8 1.7
1000 5.7 5.3 3.4 2.2
1200 7.0 6.4 4.2 2.6
1400 8.2 7.6 4.8 3.0
1600 9.2 8.8 5.6 3.4
1800 10.4 9.8 6.3 3.8
2000 11.6 11.0 7.0 4.2
2200 12.8 12.1 7.6 4.6
2400 14.0 13.3 8.4 5.1
2600 15.2 14.4 9.2 5.6
2800 16.5 15.6 10.0 6.2
3000 17.7 16.8 10.8 6.6
3200 10.1 18.0 11.5 7.0
3400 20.5 19.3 12.4 7.7
3600 21.8 20.4 13.4 8.2
3800 23.1 21.6 14.3 8.7
4000 24.6 22.9 15.1 9.4
4200 25.9 24.3 15.9 10.1
4400 27.5 25.8 16.9 10.8
4600 28.9 27.1 18.0 11.5
4800 30.4 28.4 19.0 12.1
5000 31.8 29.8 19.9 12.7
5200 33.0 31.0 20.8 13.3
5400 34.3 32.4 21.7 13.9
5600 35.7 33.7 22.6 14.5
5800 37.1 35.0 23.6 15.1
6000 38.5 36.3 24.6 15.7
TABLE D.
 
Barometrical Height Metres
15.75 1.71
17.72 1.39
19.68 1.11
21.65 0.86
23.62 0.63
25.59 0.42
27.56 0.22
29.53 0.03