Year: 1887

page_text: I, HENRY HARRIS LAKE, of the firm of Haseltine, Lake, and Co., Patent Agents,
Southampton Buildings, in the County of Middlesex, do hereby declare the nature of
this invention and in what manner the same is to be performed to be particularly
described in and by the following statement :-
Referring to the accompanying drawings
Figure 1 is a front view of my improved dial. Fig. 2 is a view in central section of
same, on plane denoted by line xx of Fig. 1. Fig. 3 is a detail view showing the
dial-card and pinion-bearing stem as removed from the case.
My invention relates more particularly to the class of sun-dials that are made in a
form for convenience in carrying about the person; and it consists in the improved
combination of the case and dial whereby the latter is adjustable.
In the drawings, the letter a denotes a case, preferably of sheet metal, of about the
usual shape and dimension of a watch-case; b, a hollow stem fast to or integral with
the rim of the case; c, a rotary shaft fitted within the stem, bearing on its outer end a
milled head c, and on its inner end a pinion, c²; d, the dial-card, having upon its lower
side an annular rack with teeth arranged to mesh with the teeth of the pinion in such
a manner that by turning the shaft, as by means of the milled head, the card will be
rotated within the case. This card has a central and circular perforation in its face
large enough to expose to view a magnetic needle, e, pivotally supported on a pin fast
to the case at about its center in such manner that the needle turns freely in the
ordinary manner. This card bears printed or stamped upon its face and next to
the opening the cardinal points, and on each side of either the north or the south point the
circle is divided in degrees to about fifteen degrees upon each side, and these divided
arcs, used for finding the true meridian, are what I call "correction-arcs." In the
annular space next outside of these points of the compass are arranged the time-lines f,

page_text: as on the ordinary sun-dial, and outside of the time-spaces is arranged a series of
numbers, from one to thirty-one, (denoted by f¹).
The glass is preferably secured below the card, so as to prevent the compass-needle
from becoming displaced, and the case may be provided with a cover attached with a
hinge, as in the manner common in hunting-case watches.
Spanning the circular opening in the card, and in line with the meridian-line of the
compass-card, is pivoted a gnomon, g, so attached to the card that it may be held in a
vertical plane for the purpose of throwing a shadow, or folded down for convenience
in closing the case.
In using this device the case is held in the hand in a horizontal plane, so that the
needle will traverse, and by means of the shaft c the dial may be turned until the
meridian-line coincides with the direction of the needle, the gnomon being raised to a
vertical plane, so as to properly 'cast, its shadow upon the time-card. This would give
the correct reading if the magnetic meridian of a place coincided with the true
meridian; but, owing to the variation of the needle some allowance must be made,
and the graduated arcs upon each side of the meridian of the compass-card are used
to measure this variation and to adjust the plane of the gnomon in the meridan of the
place where the observation is made by setting the time-card so that the needle shall
point to the proper degree, according to the magnetic variation. For example, if the
magnetic variation at the place where the observation is made is nine degrees west,
the dial-card, and with it, of course, the gnomon, should be adjusted so that the north
point of the needle shall point nine degrees west of the north point on the time-card,
when the gnomon will lie in the plane of the true meridian, and the time can be more
accurately determined by the position of its shadow. Fast to the edge of the outer
case, and pointing inward, is arranged an index-hand, a', which, by turning the
dial-card bearing the calendar f, may be made to point to the day of the month, and
by means already described the device may be made to serve as a magnetic compass,
a sun-dial, and a calander, all compactly and conveniently united in the one instrument.
Having now particularly described and ascertained the nature of my said invention,
and in what manner it is to be performed, as communicated to me by my foreign
Correspondent I declare that what I claim is :-
1. The combination of a case, a, bearing a rotary stem terminating in a pinion
within the case and a handle without, a dial-card having an annular gear in mesh with
the pinion and bearing an adjustable gnomon, and a magnetic needle arranged within
the case, all substantially as described.
2. The combination, with a case bearing a rotary stem terminating in a pinion
within the case and a handle without, of a dial-card having an annular gear in mesh
with the pinion and bearing an adjustable gnomon, substantially as described.
3. As an improved article of manufacture, the herein-described combined compass
and sun-dial, comprising the case a, a magnetic needle pivoted centrally therein, a
dial-card provided with the annular gear, the handled pinion meshing with the annular
gear and adapted to rotate the same, the adjustable gnomon, and marks and figures
upon the several parts, substantially as shown, and for the purposes described.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London,
Agents for the Applicant.