Surface compared with earth as 1.
(6) Volume compared with earth as 1.
(7) Mass compared with earth as 1.

Planets (1) (2) (3) (4) (5) (6) (7)

Mercury..... 0.88 23 to 35 1.6 3,000 0.14 0.056 0.13
Venus.....0.224 1/2 21.9 1.17 7,700 0.94 0.92 0.78
The Earth... 1.00 18.5 1.0 7,918 1.00 1.00 1.00
Mars........ 1.88 15.0 0.81 4,230 0.28 0.139 0.124
Asteroids... 3.29 .... .... From a few to 6.56
miles to 300
Jupiter..... 11.86 8.1 0.44 86,500 118.3 1309.00 316.0
Saturn...... 29.46 6.0 0.32 1,000 0.4 760.0 95.0
Uranus...... 84.02 4.2 0.23 31,900 16.3 65.0 14.7
Neptune.... 164.78 3.4 0.18 34,800 19.3 90.0 17.1
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(1) Length of day. hrs. min. sec.
(2) Length of seasons
(3) DENSITY Compared with earth as 1
(4) DENSITY Compared with water as 1
(5) FORCE OF GRAVITY AT SURFACE OF PLANET Compared with earth as 1.
(6) FORCE OF GRAVITY AT SURFACE OF PLANET Bodies fall in one second.
(7) Inclination of axis.

Planets (1) (2) (3) (4) (5) (6) (7)

Mercury. ........ ......... 1.24 7.17 0.85 13.7 .....
Venus... 23 21 22 ........ 0.92 5.21 0.83 13.4 53+
The Earth. ..... Spring, 93 1.00 5.67 1.00 16.09 23 1/2
Summer, 93
Terrestrial days Autumn, 90
Winter,89
Mars... 24 37 23 Spring, 191 0.96 2.54 0.38 6.2 27 1/2
Summer, 181
Martian days Autumn, 149
Winter, 147
Asteroids........................................................
Jupiter. 9 55 28 ......... 0.22 1.29 2.55 40.98 1 1/2
Saturn..10 29 17 ......... 0.13 0.63 1.15 18.53 27
Uranus. ....... ......... 0.18 1.41 0.91 14.6 102(?)
Neptune......... ......... 0.20 0 0.88 14.2 .....
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"You see," Ayrault explained, "on Jupiter we shall need our apergetic
outfits to enable us to make long marches, while on Saturn they will
not be necessary, the increase in our weight as a result of that
planet's size being considerably less than the usual load carried by
the Roman soldier."

"I do not imagine," said