TO TELL WHAT O’CLOCK IT IS BY THE MOON.
This may be calculated by the shadow which the moon casts upon a sun-dial, it being only necessary to know the moon’s age, which may be found in an almanack. If the new moon happens in the morning, this day is taken into the account; but if it happens after noon, the following day is counted the first. The moon’s age is to be multiplied by four and divided by five. The quotient must either be added to the hour, which the shadow indicates on the sun-dial, and the sum will give the time sought; or subtract from the quotient the hour shown by the moon upon the dial, and the remainder will give the hour sought. The first is to be done when the shadow falls on an hour of the afternoon, and the latter when it falls upon an hour of the forenoon. The following are examples:
1st. Suppose the moon to be ten days old, and the shade cast by the moon upon the sun-dial to be at half-past two; or, that the shadow cast by the moon falls on the place at which the shadow cast by the sun stands at half-past two;—what o’clock was it then? The answer is calculated as follows:—The moon’s age, 10 days × 4 = 40 40/5 = 8. Eight, therefore, is the time when the moon was in the meridian, and 8 + 2½ = 10½, or half-past ten, the hour sought.
2d. Suppose the moon to have been 18 days old, and the shadow cast by it on the sun-dial to have marked eleven. This time is subtracted from the hour when the moon was in the meridian on that day, and from which the hour marked by the shadow must be deducted. The shadow shows here 11 o’clock in the forenoon, or one hour before noon, which, deducted from 2h. 24m. gives 1h. 24m.; 2⅖ - 1 = 1⅖, or 24 minutes past one o’clock.
THE PHYSIOGNOTYPE.
This is a newly-invented instrument, by the aid of which a person may have a plaster cast of his face taken without submitting to the usual unpleasant process.
It consists of an assemblage of very fine moveable wires, confined closely together within a broad hoop or band, after the manner of the bristles in a telescope hearth-brush, but not closed at the back, in order to allow to the wires a free passage. The wires slide in a metal plate, perforated all over with holes, very fine and close together. The apparatus is surrounded by an outer case which is filled with warm water, in order to prevent any unpleasant sensation on the contact of the instrument with the skin.
