

J58 ACCOUNT OF A TIME-PIECE, 



protect it from injury. Between it and the worm is a cock g r 

 which at firft communicates with the outer air, but after hav- 

 ing produced a ftrong heat, the fleam is feen efcaping at g ; 

 by turning it a communication is opened between the worm 

 and the regulator, which then begins its operations. The bulb 

 b prevents the liquor prefled by the outer air from rifing into 

 e f e, and the alembic. It is fuperfluous to add, that, of 

 whatever form the capital may be, it fhould be well luted, in 

 order to prevent the accefs of the outer air. 



III. 



Account of a Time-Piece for regifiering the Attendance of Watch- 

 men, andforfimilar Purpqfes; conjlrudied by Mejfrs. Boulton 

 and Watt, for the Right Honourable ^cMarquis of Ex* 

 e t e R . In a Letter from h is Lord/hip . 



To Mr. NICHOLSON. 

 SIR, 



jTIAVING feen Mr. Day's account of his watchman's regu- 

 lator in your Journal, dated June], 1803, I think it may be 

 proper to inform you that a clock for a fimilar purpofe has been 

 invented by Meffrs. Boulton and Watt, Birmingham, which 

 cofts no more than thirty (hillings. I have had two of them 

 above four years. They go eight days, and have a face like 

 clock, but do not ftrike. The dial goes round, and the hour 

 finger is fixed ; round the edge of the dial are moveable iron 

 pins, correfponding with the quarters in each hour. A fmall 

 hammer placed behind the hour finger, when -moved down- 

 wards, puflies into the dial, one of the pins which happen to 

 be under it at the time, which pin remains fo abafed until the 

 dial nearly returns to the fame place, when by an inclofed 

 plane the pin is raifed up into its firft pofition. This gives 

 time to have the machine examined in the morning, to fee 

 how many pins have been ftruck, and at what time they were 

 pufhed downwards. The hammer is moved by the pulling of 

 a chain with a handle, like houfe-door bells, which, by cranks 

 and wires is attached to it. I have one in my library, the 

 handle is out of doors. The other machine is placed n a build- 

 ing 



