A MODEL OE THE SOLAS SYSTEM TO SCALE. 
101 
east to west with the apparent movement of the heavens due to 
the rotation of the planet on its axis, yet actually moves so rapidly 
amongst the stars in the opposite direction that its apparent motion 
from east to west must he very slow. The inner satellite moves 
with such extreme rapidity that it revolves round the planet nearly 
four times during each rotation of Mars on its axis. The result of 
this must he that to an observer on the surface of Mars this moon 
must rise in the west and set in the east three times during each 
day and night. I ought not to omit to mention one of the most 
extraordinary coincidences which has probably ever occurred, and 
which has reference to these satellites. In 1727 Dean Swift pub¬ 
lished his ‘ Travels of Gulliver,’ and he describes how, after visiting 
Laputa, Gulliver went to a flying island inhabited principally by 
astronomers. Swift makes Gulliver recount the discoveries of these 
imaginary astronomers, and one of these he describes thus :—“They 
have likewise discovered two lesser stars or satellites which revolve 
round Mars, whereof the innermost is distant from the centre of 
the primary planet exactly three of its diameters, and the outermost 
five; the former revolves in space in 10 hours, and the latter in 
21 and a half.” The most remarkable thing in this prophecy is 
that when, 150 years after it was published, the satellites were 
discovered, they should be found to be so nearly as Swift had de¬ 
scribed them, so close to the planet, and with such very short 
periods, the actual distances being about 1^ and 7 diameters from 
the centre of Mars. 
Saturn is the most wonderful of all the planets. There is no 
object in the heavens which, seen with a telescope of adequate 
power, is so fascinating as this. It is at the present time parti¬ 
cularly well situated for observation, and the rings are nearly as 
wide open as they can be. It will be another 30 years before the 
planet will be again so well seen. 
We must now consider the diameter of the orbits of the planets. 
Tor this purpose I have drawn a map (see Plate YI), with Watford 
Church in the centre, and I propose to imagine a model of our sun, 
7 feet in diameter, to be upon the tower of Watford Church. 
On the scale of 10,000 miles to an inch, the orbit of Mercury, the 
first planet in order from the Sun, would cross New Street, would 
pass just south of the “ Kose and Crown” and “Essex Arms,” 
through Gibbs’s shop, at the back of the Yicarage, between the 
old Tree School and Healey’s brewery, by the corner of George 
Street and Yicarage Road, and through the disused graveyard and 
the centre of Ballard’s Buildings. Mercury completes the circuit 
in 88 days, moving at the rate of 107,000 miles per hour, or 30 
miles in every second. 
Yenus, the second planet, has an orbit which would cross High 
Street by the “ Green Man,” and Queen’s Road a little north of 
the ‘Watford Observer’ office, and would pass through Chater’s 
shop, through the centre of Mrs. Rivaz’s house, and finally through 
the County Court. Yenus revolves round the sun in 225 days, 
moving at the rate of nearly 22 miles per second. 
