[ 49 6 ] 
LVI. A Difcourfe on the Locus for three and 
four Lines celebrated among the ancient 
Geometers , by H. Pemberton, M. D. R. S. 
Lond. et R. A. Berol. S . In a Letter 
to the Reverend Thomas Birch, D. D. Se- 
cretary to the Royal Society . 
S I R, 
Dec. 15. 1763. 
Read at R 
15 Dec. 1 
of the 
thought 
tion of 
nuation 
mention 
matical 
s ; TV /T Y worthy friend, and affociatc 
in my early Rudies, the collector 
late Mr. Robins’s mathematical tra&s, 
it conducive to a more compleat vindica- 
tive memory of his friend againft an infi- 
prejudicial to his candour, to make fome 
of the courfe, I took in my early mathe- 
purfuits, and how foon I became attached 
to the ancient manner of treating geometrical fub- 
jefts. This gave occafion to my looking into fome 
of my old papers, amongft which I found a difcuf- 
fion of the problem relating to the locus ad tres £? 
quatuor tineas celebrated among the ancients, which 
I then communicated to a friend or two, whofe 
fentiments of thofe ancient fages were the fame 
with mine. What I had drawn up on this fub- 
jedfc is contained in the papers, I herewith put 
into your hands, which if you fhall think worthy 
of being laid before our honourable fociety, they 
are intirely at your difpofal. 
I am your mod obedient fervant, 
PI. Pemberton. 
T PI E 
