Page:The tourist's guide to Lucknow.djvu/174

Rh would stop unless some means were provided to continue the action.

"This substitute, technically known as 'the maintaining power,' has been especially designed by the firm, and its working is as follows:—To gain access to the winding square, the attendant must first raise a lever, one end of which gears into the teeth of the great wheel, and the other being weighted, supplies the motion. The winding completed, the lever gradually drops with the revolution of the wheel into its old position. The escapement is Graham's deadbeat, the advantages of which are that, being so simple and made on such true principles, it is not easily deranged, and in the unlikely event of its becoming so, a man of ordinary capacity can rectify it, which is not the case with complicated gravity escapements. This is an important consideration for clocks in remote places, especially in the present instance, Lucknow being 678 miles 'up country.'

"The pendulum is 14 feet long, and has a bob of 3 cwt. It is compensated with zinc and iron tubes to counteract the variations of temperature.

"The rate of the new clock, which has been thoroughly tested in the factory, is reported to be a losing one of two seconds per week, so that it will give the standard time for the city and district.

"Time is shown on four dials, each 13 feet in diameter, at an elevation of 120 feet. Each dial consists of twelve openings in the brickwork, 2 feet in diameter, glazed with white opal glass, on which the numerals are marked in black enamel. The centre circle is also of the same material, and measures 5 feet 9 inches in diameter. The hands are of copper, and counterpoised on inside of tower. The minute hand is 6 feet, and the hour hand 4 feet 6 inches long.

"As it is impossible, owing to the large surface of brick-work which divides the circles, to illuminate the dials from behind, a special method has been devised for the purpose. On the bell-chamber floor above the clock-room are eight copper lanterns, two for each dial, having plate-glass fronts and silver-plated holophotal reflectors. From these reflectors a powerful stream of light is thrown upon an exterior reflector placed at such an angle as will project the light on the centre of the dial. The outside reflectors are movable, all four being extended, or withdrawn, at the same time, by an arrangement of wheels and cogs worked by the attendant.

"This system of lighting, which has been thoroughly tested before adoption, is the best under the somewhat difficult conditions in which the clock has to be illuminated,