t 520 ] r 
experimental Dull: is raifed; and yet neither Party 
can ever be brought to yield 3 for they arc both in 
the right, only they have been unlucky in giving 
the fame Name to different mathematical Concep- 
tions. Had they diflinguifhed thefe Mcafurcs of 
centripetal Force as Newton has done, calling the 
one Vis centripetee Quantitatis acceleratrix , the 
other Quant it as motrix 5 all Appearance of Contra- 
diction had ceafed, and their Propofitions, which 
feem fo contrary, had exa&ly tallied. 
VI. A Letter from Rich. Haffel£/y; F.R.S. 
to Peter Daval Efq\ Seer . R. S. concerning 
a large Piece of a Lath being thrufi into 
a Man s Eye, who recover'd of it . 
SIR, 
Read Nov. io. T* THOUGHT the following Cafe fo 
17 4 8 - extraordinary as to be worth the No- 
tice of the Royal Society. If you think fo too, I 
beg you to communicate it. 
On Sunday the 17 th of Jan. 1747* Henry Halfey , 
of South Mims, Labourer, thruff a long Lath with 
great Violence into the great Cant bus of the left 
Eye of Edward Roberts of the fame Place Labourer, 
which broke off qui te fhort fo that a Piece two Inches 
and near a half long, half an Inch wide, and above a 
quarter of an Inch thick, ( fee Tab I.) remained in his 
Head, and was fo deeply buried there, that it could fcaree 
be 
