138 ON MR. EWART’S PAPER ON THE 
paper above mentioned; giving a short account 
of the application of the principle which it re- 
commends. 
The subject of this paper formerly caused a 
great controversy among mathematicians, which 
continued for 30 years or more; and was then 
dropped, about a century ago. Since which time 
an idea has been generally entertained that it 
was only a dispute about terms. 
The advocates on one side, including Leibnitz, 
the Bernoullis (John and Daniel), Hooke, Huy- 
gens, Wolfius, Gravesande, Muschenbrook, &c., 
maintained that the force of bodies in motion 
ought to be estimated by the quantity of matter 
multiplied into the square of the velocity ; whilst 
the other side, called Newtonians, and including 
the names of Maclaurin, Pemberton, Desaguliers, 
Clark, Jurin, and Robins, contended that the 
force was as the quantity of matter multiplied 
simply by the velocity. 
To explain the reason of these opposite opinions, 
Dr. Wollaston, in his Lecture on the Force of 
Percussion, (Phil. Trans. 1806), proposes the 
following experiment : 
a 
