TRACT XXXIV.

(continued.)

NEW EXPERIMENTS IN GUNNERY.

THE EXPERIMENTS OF 1784.

68. Wednesday, July 21, SCc. 1784.

IN the course of last year’s operations we experiencedseveral inconveniences from some parts of our apparatus,which we determined to remedy if possible. These regardedchiefly the time-pieces, the axes of vibration, and themethod of measuring by the tape. For measuring the timeof a certain number of vibrations, we united the use ofa second stop watch with a simple half-second pendulum,made of a leaden bullet suspended by a silken thread,which did not always agree together. Again, the axesof the gun and pendulum frames were not found to beso devoid of friction as might be wished. But, above all,the chief cause of dissatisfaction, was the method of measur-ing the extent of the vibrations bv means of the tape; whichwas, notwithstanding all possible care and precaution, stillsubject to much irregularity, by being wetted by rain, orblown aside by the wind, or otherwise entangled, whichrendered the measurements doubtful and irregular.

The preceding part of this year therefore was employedin correcting these and other smaller imperfections in theapparatus. To our time-pieces we added a peculiar one,VOJL. III. B