(5^5 ) Number 352. 
PHILOSOPHICAL 
TRANSACTIONS, 
For the Months of Jpr'dj May^ and June, 1717. 
I. Jn Account of the Aurora Borealis, feen at Lon- 
don, on the 30th of March laft, as it teas cu^ 
riouflj ohferVd by Martin Folkes, R. S. Soc. 
II. Guilhelmi Mufgrave ^gide Societatis Socii^ de 
Britannia quondam Toene-^hifula, T> I S S B ^ 
T At 10 . 
III. Extracls from Mr. Gafeoigne’^ and Mr. Crabtrie’i 
Letters, proving Mr. Gafeoigne to haye been the 
ln\entor of the Telefcopick Sights of Mathematical 
InflrumentSy and not the French. !Bjy W. Derham, 
Prebend of Windfor, and R. Soc. Soc. 
IV. An Attempt towards the improyement of the Me~ 
thod of approximating., in the ExtraBion of the 
^oots of Equations in Numbers. (By Brook Tay- 
lor, Secretary to the Royal Society. 
V. Broprietates qu^dam fimplices Sed:ionum Conica- 
rum ex natura Focorum deduB^e 5 cum Theoremate 
generali de Virtbus Centripetis 5 quorum ope Lex Virium 
Centripetarum ad Focos SeFtionum tendentium, Velocita- 
tes CoYporum in illisreyByentium^ gs* Deferiptio Orbtum 
faciliime deter minantur. Ter Abr, de Moivre. R.S.Soc. 
X X X X L An 
