THE

LONDON JOURNAL,

AND

REPERTORY

OF

Arts, Sciences, and Manufactures.

CONJOINED SERIES.

No. CCLX.

RECENT PATENTS.

To EDWARD THOMAS LOSEBY, of Gerrard-street, Islington, horologist, for improvements in the construction of timekeepers, and in cases to be applied thereto.-[Sealed 9th December, 1852.]

THIS invention refers, firstly, to an improvement on that part of chronometers, watches, and clocks called the compensationbalance, the object being to remove a defect in the ordinary compensation, which causes the chronometer to gain in intermediate temperatures when perfectly adjusted for the extremes; on account of the balance-spring losing elastic force at an accumulating rate over the effect produced by the compound laminæ of the balance. This defect is removed by applying to the balance curved tubes containing mercury or other fluid, in addition to the ordinary compensation, the tubes being arranged in such a position as to cause the mercury, on expanding, by reason of an increase of temperature, to approach the centre of the balance at an accumulating rate, corresponding to the law of alteration in the elastic force of the spring.

In Plate IV., this novel mode of compensation is shewn in plan view at fig. 1, and in side elevation at fig. 2. a, is the bar of the balance; b, b, is the compound rim of the balance; c, c, are timing-screws; and d, d, are weights for adjusting the ordinary compensation; e, e, are the supplementary compensation-tubes, attached to the balance by the fittings f, and g, and screws h, h. i, i, are screws, which connect the parts f, and g, together, and also permit of the adjustment, laterally, of the tubes e. The action of this improvement will be bet

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ter understood by reference to the diagram, fig. 3, where the line a, represents the diameter of the balance; b, its circumference; and c, the curve of the tube tending from the bulb g, to the centre d, of the balance. e, are segments concentric with the centre d, and dividing the line representing the tube into equal parts, corresponding to the position of the mercury in equal increments of temperature. f, are lines, radiating from the centre, shewing the different inclination of each division of the tube to the radii of the balance. The progressional increase of motion in the column towards the centre, and, consequently, its effect on the moment of inertia of the balance, is shewn on the radius nearest the bulb, where it is crossed by the segments e.

The second improvement has reference to such time-keepers as are furnished with a pendulum,-the object sought being to remove the difference in the time of the pendulum's vibration between long and short arcs of oscillation. This is accomplished by adding a compensation, which increases its effect on the pendulum at the same accumulating rate as the increase in the length of the arc of vibration retards it, and thereby causes the long and short arcs to be performed in the same time. The mode of carrying out this improvement is shewn in front elevation at fig. 4, and in side elevation at fig. 5. a, is the pendulum-rod; b, is the compensating spring, supported by a clamp c, which is carried by a box g; and d, is a slide on the pendulum-rod, carrying the bar e, which is secured, in any required position, by the screw f The box g, has a glass in front, for the purpose of protecting the spring b, from injury; and it is attached to a rod h, at the back, descending from the seat-board of the clock-case, and secured at any height by the binding-screw i. A pin j, projects from the bar e, which, as the pendulum vibrates, draws the spring into an elliptical form. When this improvement is employed in turret and other large clocks, the box containing the spring is secured to any convenient part of the clock or building.

The third part of the invention refers to an improvement in the mercurial pendulum, whereby the following objects are achieved: viz., firmness of construction and portability,-the necessity for removing the mercury from the mercury vessel being avoided; while, at the same time, the mercury is preserved from oxidation and dust. The improvement consists in packing the ends of the vessel containing the mercury, as shewn in sectional elevation at fig. 6, where a, is the pendulum-rod and b, a glass cylinder containing the mercury. c, c,