AN IMPROVED APPARATUS FOR ILLUSTRATING THE MOVEMENTS OF THE EARTH AND THE MOON
Year: 1884

page_text: JOHN PETER STROESSER, living in Brussels, Rue Vifquin 28 Professor of
Mathematics and now temporarily residing at Mr. Droin's, Keston Road, 38 East
Dulwich, in the County of Surrey do hereby declare the nature of my invention
for AN IMPROVED APPARATUS FOR ILLUSTRATING THE MOVEMENTS OF THE EARTH
AND THE MOON, to be as follows:-
The apparatus illustrates the natural course of the earth and of its satellite the
moon. It indicates exactly the civil and astronomical time, the day, week and
month, the four seasons and the year, also the various lunations.
The apparatus is composed of three principal parts:
I. A pedestal or small table on which is fixed according to the astronomical
lawa
II. The plane of the ecliptic comprising
a) The ellipsis (oval) represented by a groove which is made through the plane
in proportion to the natural orbit.
b) The division of seasons which are subdivided in months; weeks and days.
c) The sun which is not placed in the centre of the oval but in proportion to the
length of the solar rays during winter and summer solstices, that is to say, in
the focus of the ellipsis.
d) The orbit of Mercury, Venus and Mars.
e) The Zodiac and various other explanatory figures, such as: the origin of winds,
the length of night and day during the four seasons, the lunar and solar eclipses.
f) The epicycloid or projection of the lunar orbit.
III. The earth which is fixed on a rod passing through the groove of the ellipses
and turns once round the sun while making about 365 revolutions upon itself.
During these revolutions, the axis of the earth represented by the rod remains
constantly vertical that is to say parallel to itself. The rod is surrounded by a
small tube to which is attached a double square at one exremity, whereas the other
extremity bears the moon. In this way the latter can turn easily round the earth.
One revolution of the moon corresponds to about 291, rotations of the earth-As
during its course, the earth keeps constantly the same inclination on the ecliptic, it
is at every moment differently struck by the solar rays and thus the gradual
variation of seasons is indicated, The seasons are represented on the ecliptic
by various colours. The whole apparatus can be put in motion either by hand or
by an ingenious clock work.

page_text: I, JOHN PETER STRŒESSER, living in Brussels, Rue Vifquin, 28, Professor of
Mathematics, and now temporarily residing at Mr Droin's, Keston Road, 38, East
Dulwich, Surrey do hereby declare the nature of my invention for "AN IMPROVED
"
APPARATUS FOR ILLUSTRATING THE MOVEMENTS OF THE EARTH AND THE MOON
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement and accompanying Drawing:-
:-
This invention has for its object an improved apparatus by which the movements
of the earth and the moon relatively to each other are easily and conveniently
illustrated.
days,
If the sun be taken as fixed, the earth turns round it in about 365
turning simultaneously on its own axis in 24 hours. The moon, being a satellite of
the earth, revolves round the latter in about 29½ hours.
From these movements are derived the division of time into days and nights,
weeks, months, seasons, and years; and apparatus has been devised for shewing
mechanically these different movements with a view to their clear comprehension,
but it has not been successful in illustrating them both theoretically and practically
by sufficiently simple mechanism.
The present invention consists of three combinations of parts carried upon a
board or foundation, as shewn at T in the accompanying drawing in which figure 1
is a plan and figure 2 a vertical section of the apparatus.
These three combinations of parts consist of 1st the plane of the eccliptic and
the sun, 2nd The earth, the moon, and the celestial meridian; 3rd the mechanism
by which they are actuated.
1st The plane of the ecliptic and the sun.
II represents the plane of the ecliptic having about 23° 27 inclination its
perimeter being an ellipse of which the point Z is the centre. bis the orbit of
the axis of the earth, forming an ellipse parallel to the perimeter of the plane II
which it divides into two parts, the outer one carried by the supports S, S, and the
inner one by the tubular centre Z the axis of which is perpendicular to the plane
which it meets at the point Z. The lower end of the tubular centre Z is carried
by supports upon the base T, its two ends being open and itself serving as a
bearing and guide for an inner spindle by which the mechanism is actuated, as
hereinafter described.
.
The plane of the ecliptic carries:-a=a ball representing the sun; and b=marks
dividing it into parts representing seasons, which are themselves subdivided into
months, weeks, and days.
d
=
There may also be marked upon it:-c=the orbits of Mercury, Venus, and Mars;
the zodiacal and other different signs, illustrative of the origin of winds, the
solar system, eclipses of the sun and moon, and so on. e= the epicycloidal path,
true and exaggerated, of the moon.
2nd The earth, the moon, and the celestial Meridian.
B represents the earth or
terrestial globe, turning round the sun in about 365 days, and on its own axis in

page_text: 24 hours whilst passing under the celestial meridian 6¹ which indicates noon for
each point of the earth passing under it.
To the globe B representing the earth is attached a pulley p¹ supported by a
hollow spindle Z' which serves as an axis for the movement of rotation.
This spindle is open at its ends and is carried by the platform or stirrup e'. The
moon is represented at c and turns round the earth in about 291%, days. It is
fixed by a bent wire to the top of a spindle n¹ which passes through and turns in
the hollow spindle Z' and is pivotted in the lower arm of the stirrup e¹ after having
passed freely through the upper arm of the latter. 61 represents the celestial
meridian and is fixed to the hollow spindle Z³.
3rd The mechanism for actuating the apparatus.
R¹ is a horizontal spindle set in rotation by clockwork, or by a handle U when it
is not necessary to show the accurate measurement of time. This spindle is
provided with an endless screw O and with a toothed bevilled wheel. A circular
plate P having 365 teeth round its edge is fixed upon the tube R³ which carries an
arm V and turns upon the inner tube Z¹.
The stirrup e with the balance weights n³ and n³ which keep it always in a
horizontal position, is capable of moving vertically and is connected to the arm V
by an elastic string e¹ which allows it to remain always in the same position
opposite the orbit of the axis of the earth. A wheel or pulley n fixed upon the
spindle n¹ is guided by the vertical cylinder N, the upper edge of which is cut
parallel to the plane of the ecliptic, its central axis passing through the point z.
This wheel n is kept pressed against the guiding cylinder N by the action of the
elastic string e' on the stirrup e¹ and as it moves round the cylinder its friction
against the latter causes it to revolve together with its axle n¹, and the moon o
which is carried by the latter consequently also revolves round the earth.
The diameter of the wheel n is so proportioned that whilst the axis of the earth
moves through 29½ times 1/365th part of its orbit, the wheel makes one complete
revolution.
An axle R² arranged as shewn carries two bevilled toothed wheels g₁ and g³ each
having the same number of teeth as the wheel g¹, and a spindle R* which turns in
the hollow spindle Z' has at its lower end a fourth similar wheel 9 of the same
number of teeth, and at its upper end--after passing through the ecliptic plane,-a
needle or hand Q and a pulley p'. A flexible cord x connects the two pullies
p' and p which are of the same diameter.
Upon the plane of the ecliptic are added the lines AI and A M which mark the
winter and summer solstices, and the lines A F and AK, for the spring and autumn
equinoxes.
The triangles IAK, MAK, FAM, and FA I, shew the four seasons, summer,
autumn, winter, and spring.
The triangles D A D₁, D' A E, EA E¹, E¹AG, GA G¹³, Œ¹A H, HA H¹, H¹AJ,
JAJ, JAL, LA L, LA D, define the months, January, February, &°. The
graduations 5, 10, 15, 20, 25, on the orbit shew the days of the month and the
Roman figures I, II, III, IV, & the hours.
It will be seen that if the axis R¹ makes one turn in 24 hours, the endless
screw turns the plate P through one tooth, that is to say 1/365th part of a
revolution, in the same time, and the arm V also drives the stirrup e, and the
spindle Z which carries the earth through 1/365th part of the terrestrial orbit, and
the earth will therefore move round the sun in 365 days. The spindle n¹ which
O turns in the hollow spindle will also advance in 24 hours through 1/365th part
of the terrestrial orbit, and in its movement will take with it the wheel n which by
its friction on the cylinder N will, together with its axis n¹ and the moon c carried
by the latter, make one complete turn in 29, days. The axis R' making one
complete turn in 24 hours the spindles R' and R will also make one turn in the
same time and the needle or hand O will also revolve once in 24 hours and will

page_text: similar movement to the pulley p³ and to the earth B which will therefore turn in
'the same time.
The earth, therefore, will revolve round the sun in 365 days, at the same time
turning on its own axis every 24 hours, and the moon whilst following the
movement of the earth round the sun, will also revolve round the latter once
in 291/, days.
In this way the movements of the several bodies are accurately indicated by
*simple and easily made mechanism.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is
1. The combination of the inclined plane II having the concentric opening b, the
spheres B and C representing the earth and moon respectively, carried and actuated
by the spindles n', the balanced supporting stirrup e¹, the wheel n and guiding
cylinder N, the arm V, tubular axis R³, toothed wheel P, and endless screw
on the driving axle R¹, all arranged and operating for the purpose described
and shewn.
2. The combination of the driving axle R¹, toothed bevilled wheels g¹, g³, g', gʻ,
spindles R, R, indicating hand Q, pullies p', and p², and endless cord x, arranged
and operating for the purpose described and shewn.