174 Mr. Vince on the Motion of 
of the body upon the fame fur face, it is not liable to any inac- 
curacy of the kind which the preceding cautions have been 
given to avoid, nor indeed to any other, and therefore it mud: 
be perfectly, conclufive. In the following experiments the 
cautions mentioned above were carefully attended to. 
Exp. i. A body was taken whofe flat furface was to its edge 
as 22 : 9, and with the fame moving force the body defcribed 
on its flat fide 33 \ inches in 2", and on its edge 47 inches in 
the fame time. 
Exp. 2. A fecond body was taken whofe flat furface was to 
its edge as 32 : q, and with the fame moving force it defcribed 
on its flat flde 32 inches in 2", and on its edge it defcribed 37 \ 
inches in the fame time. 
Exp. 3. 1 took another body and covered one of its furfaces, 
whofe length was 9 inches, with a fine rough paper, and by 
applying a moving force, it defcribed 25 inches in 2 " ; I then 
took off fome paper from the middle, leaving only of an inch 
at the two ends, and with the fame moving force it defcribed 
40 inches in the fame time. 
Exp. 4. Another body was taken which had one of its fur- 
faces, whofe length was 9 inches, covered with a fine rough 
paper, and by applying a moving force it defcribed 42 inches 
in 2 // ; fome of the paper was then taken off from the mid- 
dle, leaving only 14. inches at the two ends, and with the fame 
moving force it defcribed 54 inches in 2"; 1 then took off 
more paper, leaving only \ of an inch at the two ends, and 
the body then defcribed, by the fame moving force, 60 inches 
in the fame time. 
In the two laft experiments the paper which was taken off 
the furface was laid on the body, that its weight might not be 
altered. 
Exp. 
