( >99 ) 
By this Obfervation the Beginning differed not x ^ 
and the End not | a Minute from Dr. Halkys Com- 
putation, which he lent me the Day before. And if his 
Computation, which was made for Greenwich^ had 
been reduced to the Meridian of London-^ the Diffe- 
rence would have been Hill lels. 
The fame Ecliffe was obferv" d by Mr. Hawkins at 
Wakefield, in Yorklliire, to begin at ih. xim. p. m. 
and to eud at m. ^ 'f. The Sun' sTyiameter was 
obfcured fomewhat more than 5* T)igits, 
III. De Tarticulis ^ StruBura Jdamantum. Epi^ 
ftola Domini Antonii Leeuwenhoek, <2^. S.Soc. 
ad Jacobum Jurin, Mi D. ^ S. Secret, 
P Oftquam invelligando compereram Metalla quse- 
dam, & iplas etiam Arenas ex perexiguis ejuf- 
dem materise particulis compofitas effe, meditatio- 
nem meam converti ad Adamantem ; fcilicet niim ille 
etiam ex iftiufmodi conllet particulis, quse quidem ope 
microlcopii conlpici poffint. 
Igitur exiguum quendam Adamantem per microlco- 
pium contemplatus, in ea Adamantis parte quae polita 
non erat, & Iplendore carebat, complures particulas 
ociilis oblervavi ; & Adamantem ex parvis particulis 
compofftum effe comperi. Verum cum haec nondum 
mihi latisfacerent ; Adamantem in fmffa confringere 
decreVi, ut ilium in fragments fuis confiderarem. 
Ergo Adamantem, malleo impofitum, alio nialleo 
lemel iterumque percuffi, qui fic percuffus in quatuor 
aut quinque frufta diffiliebat. Quod cum nondum 
mihi fatisfacerer, & Adamantem in exiguiffimas micu- 
las comminuere vellem ; fruffum, quod caeteris majus 
K k X erat, 
