(98) 
and that of Septate us mud fcatter them in the cooipafs ot 
three Inches, Some here do intend to make of them^ yea 
and bigger ones 5 but we muft ftay till they b« done, c^c. 
Of Monfieur Heytlim s Promi^^ of impming to 
the World his Invention of making Optick 
Claffcsi and of the hopes given by Monflem 
Hugcns of X\iXic\\Qm-f to perfom fomething of 
t]}e like nature *^ as alfo of the ExpeStations ^ 
conceived of fome Ingenious Ferfonsin England, 
to improve Telefcopcs. 
That eminent Aflronomer of Dd^jtzkk^ Mpnffeur lieve" 
iJuf-, writes to his Gorrefpondcnt in Londet?^ as followeth : 
What hath been done in the grinding of Qptick glaffes 
in your parts, and how thofe beginniog^j snention'd by 
you formerly^ do continue and fucceed, I very much covet 
1:0 hear. Tis now above ten Years, fince I my felf invent- 
ed a peculiar tray of grinding fuch GUffes^ and reduced it 
alfo into praftife^ by which 'tis eafie, without any confider- 
able danger of failing, to make and polliQi Optick glaffes of 
any C^^^/V^ Sediqnj and that (which is moft not^bft) in any 
difti of any Seftion of a Sphere : which Invention I have as 
yet difcovered to none, my purpofe being, for the Improve- 
ment of Natural Knowledgej to defcribe the whole me- 
thod thereof in my Celejlial Machine^ and to propofeit to 
the Examination and Judgement of the Royal Society not 
doubting at all, but they will finde the way true and pra- 
fticablej my felf having already made ftveral Glaffes by it, 
which many Learned Men have feen andtryed. 
Monficur Hftf^e^y, inquiring alfo in a Letter^ newly writ- 
ten by him to a Friend of hi^ in EngUndy of the fuccefs of 
the attempts made by an Ingenious Englijh Man for perfeft- 
ing fuch 01«ffc5;> aod urging the profccution of the fame,. 
fo 
