1852.] OF THE ROYAL INSTITUTION. 111 
the rate of a tooth each second, and the axis of this ratchet wheel 
carries the pinion which moves the other wheels of the clock. 
The circuit of the battery connected with the striking part of the 
clock is only completed once in an hour, and is connected with an 
electro-magnet so arranged, as by means of a proper lever to pull the 
ratchet wheel attached to the notched striking wheel one tooth 
forward every two seconds, and each tooth is accompanied by a blow 
on the electro-magnetic bell. The number of blows depends upon the 
notched wheel, the spaces on the circumference of which are adapted 
* to the number to be struck, and when this is complete, a lever falls 
into the notch, and in so doing cuts off the electric current, which is 
not re-established through the striking electro-magnet, till the next 
hour, when a peg upon the hour wheel pushes the striking lever 
forward so as to cause it to be depressed by a similar peg upon the 
minute wheel. 
Such is an outline of the mechanism of these clocks; but it is 
impossible to render further details upon the subject intelligible 
without reference to diagrams. A very large working model of the 
clock and of the striking apparatus, constructed for the occasion by 
Mr. Shepherd, was exhibited in the Theatre, as well as a model of 
the pendulum and its appendages made under the direction of Mr. 
C. V. Walker, to whom Mr. Brande was also indebted for a signal 
bell, upon the principle of Mr. Shepherd’s clock bells, for the purpose 
of giving notice to the railway switchmen of the approach of trains 
in foggy weather. 
Mr. Brande concluded by describing the arrangement of Mr. 
Shepherd’s clocks as adopted in the extensive warehouse of Mr. 
Pawson in St. Paul’s Churchyard, where eight dials are maintained 
in action by an electro-magnetic pendulum in the counting-house, 
and adverted to the Electric Clock at the Tunbridge Station of the 
South Eastern Railway, and to the intention of the Astronomer 
Royal to establish one at Greenwich for the purpose of sending time 
signals to the different Metropolitan Railway Stations, and to the 
Palace at Westminster. 
CW... TB 
In the Library were exhibited : 
Wheatstone’s Wave-line Apparatus. [Exhibited by Mr. Appold.] 
Baleniceps Rex, the King Stork, from the Interior of North 
Africa, the property of Mansfield Parkyns, Esq. M.R.I.; and 
a Group of Humming-birds. [Mounted and Exhibited by Messrs. 
Leadbeaters]. 
Head of a Walrus from the Arctic Regions — a Mandingo Dagger — 
a Model of the Milk-yoke Knapsack, and other objects, from the 
United Service Institution. 
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