1838.] On the Rate of a Clock with a Wooden Pendaluni. 109 



fir, for which I sent to London some years ago, for the purpose of 

 making barrels for a small self-performing organ; a purpose which 

 required pine or fir of good quality. It had been freely exposed to the 

 air in the verandah of a bungalow for four or five years, and I have 

 reason to think that it vi^as pretty well seasoned, as the land winds for 

 five successive seasons had blown freely upon it. 



5. — Nothing in the arrangement or construction of the clock was 

 new, so as to call for particular notice ; the second and hour hands had 

 small subordinate dials to themselves, and the minute hand swept 

 round the large dial, or face of the clock. The pendulum bub was of 

 lead and weighed 12-lbs. avoirdapoise ; the going weight of the clock 

 was 5-ibs., and the swing of the pendulum kept steadily within from 

 2^ 0' to 2° 3' or 2° 4', on each side the centre of the arc of vibration. 

 hs the firm suspension of the pendulum is however an important part 

 in the putting up of a correct time-piece, I may mention the manner in 

 which I effected this point. The clock-case had for its back-board, a 

 fine solid plank of teak, 18 inches wide, and one and a half inch thick. 

 The sides of the clock-case were glued and screwed to this plank, so 

 that the whole was very substantial. The plank was secured by bolts 

 to the wall of the room in which the clock was placed. A block of 

 wood about six or seven inches long, and an inch and a half thick, was 

 glued and screwed with six strong S-inch screws to the back plank, at 

 the proper height for suspending the pendulum, which was supported 

 from this block by two screws that, passing through it from the top, 

 were tapped into the brass beneath (PI. C, fig. I), which will shew at a 

 glance how the pendulum was suspended; and though the mode was 

 simple I found it very secure. 



6. — The following table shews the mean-time rate of the going of 

 the clock, in seconds and tenths of seconds daily. The asterisks are 

 intended to denote the days on which observations were taken. The 

 observations consisted simply in taking the time of the clock at even- 

 ing gun-fire, — gun-fire time being taken also at the Madras Observatory, 

 and then obtaining the mean time of gun-fire from the Observatory, 

 and reducing the rate of the clock from it. 



