IMPROVEMENTS IN APPARATUS FOR MEASURING AND INDICATING TIME
Year: 1872

page_text: PROVISIONAL SPECIFICATION left by Michael Henry at the Office of
the Commissioners of Patents, with his Petition, on the 19th July
1872. A communication from abroad by Jules François Gouéry
and Jacques Bigourat, both of 17, Boulevart Saint Martin, Paris,-
France.
I, MICHAEL HENRY, of Fleet Chambers, 68, Fleet Street, in the City
of London, Patent Agent, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN APPARATUS FOR MEASURING AND INDICATING
TIME," communicated to me from abroad by Jules François Gouéry
and Jacques Bigourat, both of 17, Boulevart Saint Martin, Paris, France,
to be as follows :-
The Invention consists of an apparatus or instrument for measuring
and indicating time by the combined means of the sun and a magnetic
needle, that is to say, by means of the varying positions of the sun'
when above the horizon; with respect to the position of a magnetic or
magnetized, needle, which always points in one direction, the apparatus
being so contrived that at a determined time, say, 11 hrs. 15 min., the

page_text: Shadow projected by a rou, arm, pm, andade, of them on a conta
plane or dial shall accurately correspond with the direction of the needle.
The instrument thus serves not only for measuring and indicating time,
but also for shewing direction or position with regard to the points of
the compass.
;
In carrying out the Invention the apparatus may be so constructed
that the time shall be measured and indicated on a graduated horal dial,
by means of the position of the needle with regard to a fixed line, which
is marked on the dial and forms an initial or starting mark corresponding
with and registering the projection or prolongation of a shadow thrown
at a certain hour.
In order that the Invention may be fully understood, I proceed to
describe particularly one practical mode of constructing such an
apparatus.
On a dial I fit an arm, bar, rod, or piece having a slot therein; it is
a sort of slotted alidade, transom, or cross staff; it may be straight or
set at any angle between 0° and 90°. The projection on the dial of the
slot is observed and registered or indicated by marking a line corre-
sponding therewith on the dial in a distinct and perceptible or prominent
manner; it is best to mark it in a bright colour. In the centre of the
dial is fitted a compass with its needle. The parts of the instrument are
so arranged with respect to each other, that at 11 hrs. 15 min., the
direction of the projection of the slot shall correspond with the direction
of the needle. The dial is divided by the line into two semicircular
portions, and each portion is graduated or marked off into 12 divisions
corresponding with hours, each of which may be subdivided into minutes
and seconds if the size of the dial permit..
. When at any time of the day the dial is so placed that a ray of sunlight
passing through the slot of the arm or alidade shall correspond with the
line or mark on the dial, the hour will be indicated by the direction of
the needle which will of course at the same time also shew the direction
or position of objects according to the points of the compass.
However the arrangements or details for carrying out the Invention
may be varied, for instance, the contrivance may be enclosed in a watch
case, and the bar, rod; or alidade may be jointed so as to be raised only

page_text: when one wishes to consult the dial in order to ascertain the time. Or
instead of using an alidade, a needle, pin, or tongue may be employed,
its shadow corresponding with the prominent line aforesaid. Or instead
of the alidade, a slot may be formed in the case of the watch or instru-
ment.