(123:) 
fticuld not appfcar b the like manner. But, I will determine 
nothing of any of thefe things. When I fliall hereafter have 
made more frequent Obfervations of the Moon with my 
great Telefcopes^ in convenient time, I fhall then perhaps learn 
more of it, than I know at prefent, at leaft it will excite the 
Cumusto endeavor to make the like Obfervations 5 and it 
may be, othcr$5 that I have not thought of. 
T^he Infiance of the fame Perfon to Mr* Hook^ for 
communicating his Contri'uance of mah^ngywith a 
Clafs of a Sphere of zo or 40 foot diameter,^ Te«. 
Icfcopc drawing fez^eral hundred foot ^and his of-^ 
fer of recompenfing that Secret with another ^teach- 
ing to meafurewith ^Telefeope the Diftanccs 
oi 0^y)cdis upon the Earths 
In Numb. Of thcfe P^perf^ pag. 67. Mr. Hook, had inti^- 
fsiatcd 5 th^r he would (faortly difcovcr a way of hiSj with a 
plane''C0Mt?exC\2LSe of a Sphsere of 20. or 40. feet Diameter^ 
without ^^i^e/j and truly wrought of that F/^wre^ to make 
a T(r/^/r(?pe, that with a fingle Eye-glafs fliould draw 500^ 
400, yea looo feet, without at all altering the Convexitj : 
Monfi^ur Aazout returns this confideration, and ojffer iipon 
it, which follows* 
To perform (faith he) with a lefer Ohje& -glafs the effeft of 
a great Telefcope ^ we muft find oat a way to. make 
fuch an 0b]e3''glafs to receive as many Rayes as one will^ 
without their being fenfibly diftant from one another 5 to 
the end, ihat by applying to it a ftronger Eje^glafs^ there 
may be ftill Beams enough to fee ^he Objed:, and to oblite- 
rate the fmall fpecks and imperfcfiions of the Ej/' -glaff, 
And if Mr. Hookhzth this Invention, I efteem it one of the 
^reateflr, that can he found in the matter of TetefcopcK if 
he plcafc to impart it to us? we fliall be obliged to him 5 and 
