CLOCK. 44 CLOCK. the completion of every hour; when the minute- wheel, which revolves once in an liour, and car- ries the miuute-liand of the clock along with it, brings it into action by the temporary release of a catch or detent, permitting the weight wound up on the cylinder of the striking apparatus to run down a little, in doing which the ham- )ncr is forced into action, so as to strike the bell. W hether the strokes shall be one or many is de- termined principally by two pieces of mechanism, one called a 'snail,' from its form or outline, with twelve steps, and the other a 'rack,' with twelve teeth. The time during which the strik- ing-weight is allotccd to descend varies accord- ing to the turning of the twelve steps of the snail on its axis, and the position of the twelve teeth of the rack at different hours of the day, being sometimes only long enough to permit one blow to be given by the hammer on the bell, and at another time long enough for twelve such blows. It is not known when the alarm or when the striking mechanism of the clock was first ap- plied. The alarm was adopted for the use of the priesthood, to .arouse them to their morning de- votions. The first striking clock probably an- nounced the hour by a single blow, as they still do, to avoid noise in churches. During the seven- teenth century there existed a great taste for striking clocks, and hence a great variety of them. Several of Tompion's clocks not only struck the quarters on eight bells, but also the hour after each quarter; at 12 o'clock 44 blows were struck, and between 12 and 1 no fewer than 113. ilany struck the hour twice, like that of Saint Clement Danes, in the Strand, London. Before the fifteenth century chimes had been in- trodxiced. (See Cuimes : also an article in the Journal of the Society of Arts (London, March 29, 1901), on "Clocks, Carillons, and Bells.") Clocks Provided wnn Automatons. The de- sire to construct clocks which shall perform auto- matically manv other things besides simply re- cording the time of day is as old as clockmak- ing, and was developed to a wonderful degree in the ancient clepsydne of Oriental nations. In- deed, the automatons of the ancient Chinese and Arabian clocks were the models upon Avhich all those of media?val Europe, including the famous Strassburg clock, were based. Among the earliest of these automatons or 'jacks of the clock' built in the to«er-clocks of Europe were those of the clocks at Dijon, Cambrai, and Linden, in each of which two figures appear and strike the hour- ly bell. In 1495 the clock at Liibeck was built in which the figm'es of the Twelve Apostles were introduced. Probably the most widely know-n of these tower-clocks is the one in Strassburg Cathedral. This famous clock has been reconstructed twice. The first Strassburg clock was built in 1352, under the direction of .John. Bishop of Lichten- berg. It contained a calendar, an astrolabe, and a set of chimes composed of several cymbals. There were automatic figiires of the Vi'rgin. of the three Vise ilen who bow before her, and a cock, which moves its beak, crows, and flaps its wings. The second Strassburg clock was built in 1570. Its mechanical works were constructed by Isaak and Josias Habrecht, of Schaffhansen. Switzerland. Early in the nineteenth century it was found that the clock required reconstruc- tion, and the task was consigned to Charles .Schwilgue, who consumed four years in its com- pletion. Only a few of the original movements were restored by Schwilgue, most of the present mechanism being of his own design. The following description of the present Strass- burg clock indicates its most important fea- tures: It is 30 feet high and 15 feet at the base. On one side of the main portion is a flight of winding stairs, surmounted bj' five columns. On the other side is a Gothic pil- lar, the panels of which are filled with fig- ure paintings. At the Ijase of the main Fir. 5. .STRASSBURG CATHEDRAL CLOCK. ))ortion of the clock is a celestial globe, in- dicating sidereal time, and showing tlie rising, passing over the meridian of Strassburg, and setting of all stars that appear above the horizon, visible to the naked eye. Behind the globe is a calendar, showing the day of the month and the fixed and movable feasts. A statue of Apollo points out the day of the month. The calendar is in the form of an annular band, so arranged as to show' many other astronomical events be- sides the day of the month. Above the cal-
