IMPROVE- MENTS IN SOLAR TIME-KEEPERS OR CHRONOMETERS
Year: 1861

page_text: LETTERS PATENT to Richard Archibald Brooman, of 166, Fleet Street,
in the City of London, Patent Agent, for the Invention of "IMPROVE-
MENTS IN SOLAR TIME-KEEPERS OR CHRONOMETERS."-A communication from
abroad by Paul Fléchet, of Paris, France..
Sealed the 31st October 1861, and dated the 2nd May 1861.
PROVISIONAL SPECIFICATION left by the said Richard Archibald Brooman.
at the Office of the Commissioners of Patents, with his Petition, on the
2nd May 1861.
I, RICHARD ARCHIBALD BROOMAN, of 166, Fleet Street, in the City of
London, Patent Agent, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN SOLAR TIME-KEEPERS OR CHRONOMETERS," (communicated to
me from abroad by Paul Fléchet, of Paris, France,) to be as follows:-
The use of this solar chronometer is general, and extends to all quarters of
the globe. It gives the hour in true and mean time, without the aid of any
table of corrections; it also indicates the meridian, as well as the latitude of the.
spot where it is used, and it corrects or regulates itself by itself. It is illus-
trated in the accompanying Drawings, of which Figures 1, 2, 3, 4, and 5 are.
the different views thereof, and is composed of four principal parts A, B, C,
and D; that marked A, Figures 1, 2, and 5 represents a stand supporting the.
apparatus and resting on adjusting or regulating screws v; e, e, is a column
or upright serving as an axis to the piece B. This piece, which is shown at:
Figures 1, 2, and 3, and in dotted lines at Figure 5, is fitted to the upright
e, e, and receives on its face r, s, the piece C, which is there fixed by means of.

page_text: a bolt f, forming an axis. By tightening the pressure screw g the piece B is
prevented from rotating round the upright e, e, and by turning the bolt f the
piece C is prevented from rotating on its axis. The piece C is bored to
receive the axis h, h, Figure 1. The circumference of this piece C is turned
with h, h, for its axis, and is divided into 24 equal parts indicating the two
periods of noon to midnight, and from midnight to noon, as shown at Figure 5.
Each division, which represents an hour, is subdivided. The plane passing
through the axis h, h, and the whole corresponding to noon, is parallel with
the face r, s. The piece D is free to pivot about h, carries at i a lens, and a
spherical part 1, l, of which the lens i would be the centre and a vernier.
Through the axis h, h, and the point i, the centre of the lens, take a plane as
indicated by m, n, in Figure 4, and by 1; 1; in the diagram Figure 1bs, the
beginning of the vernier is in this plane, as well as two notches t and u,
Figures 1 and 4, to receive the stretched thread t, u, which will also be in the
plane h, h, i, 1, 1. Through the point i a second plane is drawn perpendicular
to h, h. The cross line k, k¹, on the spherical part 1, 1, Figure 1bis, will be the
equinoxial line. With the assistance of these two lines 1, 1, and k, k¹, I draw
the curve l, k, l, k, of the equation of time for each day of the year after the
Annual of the Bureau des Longitudes, and for the focal distance i, l, from the
lens. The line 1, 2, represents true time: The parts are constructed in such
manner, 1st, that the upright axis e, e, of the piece A can be brought into and
maintained in a vertical position; 2nd, that the piece B may turn about the
upright axis e, e, and be secured to the piece A by the pressure screw g;
3rd, that the piece C may turn about the axis f, and that by screwing up the
bolt fit can be fixed to the piece B; 4th, that the piece D may turn about
the part h, h, and that it may participate in the rotary motion of the piece C
about the bolt axis f, f, as well as in the rotary motion of the piece B about.
the upright e, e.
The three motions are independent of one another, and they
can be combined or not by the screw g and bolt f. It is indispensable, 1st,
that the bolt be in a plane perpendicular with the upright e, in order that
the face r, s, on this axis be parallel with the upright e, e; and 2nd, that the
axis h, h, of the piece C be parallel with the face r, s, of the same piece; if
then the upright e, e, is vertical, the face 2, 8, will also be vertical, and what-
ever the position given to the piece B and to the piece C, the axis h, h, will
be in a vertical plane.
Operation of the instrument. Supposing it to be resting on the regulating
and adjusting screws, turn the piece D to bring the zero on the vernier to
noon, stretch the thread t, u, and suspend from it the plumb line æ, y. The
line t, u, is common with the two planes, h, h, i, 1, 1, and t, u, a', y; now

page_text: bring by means of the adjusting screws the first of these planes vertical,
making it blend with the second, and that in different positions, so as to be
certain that the column e, e, is vertical; that determined, the picce A is
definitely fixed in that position, and the plumb line is removed. In order to
give the piece C the desired inclination, maintain the zero of the vernier at
noon, and draw the focus of the lens on the point of curve corresponding to the
day on which the operation takes place. Tighten the bolt f; f, the inclination
of which piece must not again be varied for the particular latitude. The appa-
ratus may be turned towards the east at any time, but it is at six o'clock in the
morning or evening that the operation affords the greatest exactness." Without
unscrewing the bolt f, f, bring the focus of the lens i upon the point cor-
responding to the day on which the operation is being performed, the appa-
ratus will be in position, and the vernier will give the hour.
there are two positions, possibly it is necessary to choose that
vernier is to the right of noon, if the operation takes place in the evening.;
and that where the vernier is to the left of noon, if the operation takes place in
the morning. The piece B is fixed by tightening the screw q; the piece D
alone remains movable, and the vernier will give the hour mean time when
the focus falls on the curve; it will give the true time when the focus appears
on the right.
However, as
in which the
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
•
by the said Richard Archibald Brooman in the Great Seal Patent Office
on the 2nd November 1861.
TO ALL. TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
ARCHIBALD BROOMAN, of 166, Fleet Street, in the City of London, Patent
Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the. Second day of May, in the year of our Lord
One thousand eight hundred and sixty-one, in the twenty-fourth year
of Her reign, did, for Herself, Her heirs and successors, give, and grant
unto me, the said Richard. Archibald Brooman, Her special licence that
I, the said Richard Archibald Brooman, my executors, administrators, and
assigns, or such others as I, the said Richard Archibald Brooman, my
executors, administrators, and assigns, should at any time agree with, and
no others, from time to time and at all times thereafter during the term
therein expressed, should and lawfully might make, use, exercise, and

page_text: vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN
SOLAR TIME-KEEPERS OR CHRONOMETERS," (a communication from abroad by
Paul Fléchet, of Paris, France,) upon the condition (amongst others) that
I, the said Richard Archibald Brooman, my executors or administrators,
one of their hands
by an instrument in writing under my, or their, or
and seals, should particularly describe and ascertain the nature of the said
Invention, and in what manner the same was to be performed, and cause
'the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Richard Archibald Brooman, do hereby
declare the nature of the said Invention, and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
"statement thereof, reference being had to the Drawings hereunto annexed,
that is to say:-
This solar chronometer may be used generally, and in all quarters of the
globe; it gives the hour in true and mean time without the aid of any table
of corrections; it also indicates the meridian as well as the latitude of the spot
where it is used; and it is self-verifying. It is illustrated by the accompanying
Drawings, Figures 1, 2, and 3. It is composed of four principal parts A, B,
C, and D.
an
A (Figures 1 and 2) represents a stand having a hole in it for attaching and
adjusting the instrument in a horizontal position on any suitable bed plate; e is
a projecting piece with vertical front, against which the part B is fitted and
secured by
axis f, about which it is free to move a screw, keeping it fixed
when desired; g is a socket in the part B into which the axis h of the spherical
'cap C takes. The upper circumference of this cap C is divided into 24 equal
parts, indicating the two periods of from noon to midnight, and from midnight
to noon, as shown at Figure 4. Each division which represents an hour is
subdivided for the quarters and minutes. The plane passing through the line
of axis h, h, and the whole corresponding to noon is parallel with the. vertical
'face. The pieces D, D¹, are fixed to the spherical cap by screws, that marked
D carries a lens i, and that marked D' is a section of a sphere 1, 1, of which the
lens is the centre; vis a vernier on the cap C. Through the axis h, h, and
the point i the centre of the lens a plane passes, the trace of which is shewn by
'm, n, in Figure 4, and by 1, l, in the projection Figure 1 of the spherical.section;
the beginning of the vernier is in this plane as well as two notches t and u,
Figures 1 and 3, which receive the stretched thread t, u, and which will also
-be in the plane h, h, i, 1, 1. Through the point ia 'second plane is drawn

page_text: perpendicular to h, h; its trace k, k', on the projection of the spherical section
1, 1, Figure 5, will be the equinoxial line. The two lines 1, 1, and k, k¹, being
obtained, I draw the curve; 1, k, l, k, is traced, showing the equation of time
for each day of the year according to L'Annuaire du Bureau des Longitudes,
and for the focal distance i, l, from the lens. The line 7, 1, represents true
time.
: :
The parts are constructed in such manner, first, that the piece A can bo
brought into and maintained in a horizontal position; second, that the piece B
may turn vertically about the axis f, and. be secured to the piece A by a
pressure screw; third, that the piece C may turn in a plane perpendicular to
that of B about the axis h, and may by a screw be fixed to the piece B;
fourth, that the pieces D, D', being fixed on the spherical cap C may participate
in the vertical rotary motion of the piece B about the axis f. These motions
Care independent of one another, and they can be combined or not by the screws
and tightening bolts. It is indispensible, first, that the axis f of the piece B be
in a plane perpendicular to the vertical face of the disc e, projecting piece in
.the support A; and second, that the axis h, h, of the piece C be parallel with
the vertical face of the projection on the support A and of the piece B. If
then this upright face is vertical, whatever position is given to the piece Band
to tlie piece C, the axis h, h, will always be in a vertical plane.
In
The operation of the instrument is as follows:-Supposing it to be resting
on the horizontal support A, turn the piece C to bring the zero of the vernier
to noon, stretch the thread t, u, and suspend from it the plumb line x, y. The
line t, u, is common to the two planes h; h, i, 1, 1, and t, u, x, y, which is
5 rendered vertical by making the two planes to coincide, and that in different
positions, so as to be certain that the plane is vertical. That determined, the
piece A is definitely fixed in that position and the plumb line is removed.
order to give the piece B the desired inclination at mid-day, place the zero of
the vernier at noon and bring the focus of the lens on the point of the curve
O corresponding to the day on which the operation takes place, tighten the axis,
the inclination of which piece must not again be varied for the particular
latitude. The apparatus may be oriented or set to mark the bearing or
*situation with respect to the four cardinal points at any hour, but it is at six
o'clock in the morning or evening that the operation affords the greatest
5 exactness. Without displacing the axis f bring the focus of the lens i upon the
point of the curve corresponding to the day on which the operation is being
performed, the apparatus will be in position, and the vernier will give the hour;
however, as there are two positions possible, it is necessary to choose that in
which the vernier is to the right of noon if the operation takes place in the

page_text: evening; and that where the vernier is to the left of noon, if the operation
takes place in the morning, the piece C alone remains movable, and the vernier
will give the hour mean time when the focus falls on the curve, and it will
give the true time when the focus fall on the straight line.
When the instrument is at work the three pieces are:-One horizontal
corresponding with the bearing in respect to the cardinal points; one vertical
'corresponding with the latitude; the third equinoxial corresponding with the
hour. One of these quantities being known, the instrument gives the other
two by the sun. If a compass is used to ascertain the bearing with respect to
the cardinal points, the instrument will give the latitude and the hour. By
comparing the hour of the place with that of the first meridian given by a
'chronometer, the longitude can be ascertained, and consequently the geo-
graphical position of the place where the operation takes place.
For purposes of instruction, the piece carrying the vernier can be replaced
'by a terrestial globe, and placed in such manner that all its circles would be
parallel with analogous circles on the earth, so that when the sun shines all the
lighted parts on the earth will have their analogous parts lighted on the globe.
It is very interesting to watch on this terrestial globe the sun rising and
-sitting.
The instrument may be made of inoxydizable metal, and enamelled, and
parts of it, such as the cap C may be of glass or other material.
And having now described the nature of the said Invention, and in what
manner the same is to be performed, I declare that I do not limit myself
to the particular arrangement and materials herein-before described, for the
same may be varied without departing from the Invention; but what I claim
is, the improvements in solar time-keepers or chronometers, substantially as
herein-before described and illustrated in the accompanying Drawings.
In witness whereof, I, the said Richard Archibald Brooman, have
hereunto set my hand and seal, this Second day of November, One
thousand eight hundred and sixty-one.