C453 J 
Ati Account $f an Obfervation of an Eclipfe of the Moon, ob- 
served at Mofcua in Ruffia, on April 5-. 1688. compa- 
red with the fame obferved at Lipfick 3 whereby the Lon- 
gitude of the former place is afcertained : Together with 
the Latitude of fever al principal Places in the Empire of 
Ruffia. 
THE Royal Society being defirous to contribute 
what they may to the rectifying of Geography, 
and determining the Longitudes of Places, amongft others 
did recommend the procuring an Eclipfe to be obferved 
at Mofcua , to an eminent Merchant trading there 3 at 
whofe inftance one Mr. Timmerman 9 a Mathematician, 
refiding on the place, returned the following account. 
April 5. 1688. half a quarter of an hour after feven 
in the Evening, the Moon arofe clear, but of a deep 
red colour without any fign of Eclipfe : at y h h the Moon 
went iato a thick Cloud, but was again clear at y h 38* 
when the under-fide of the Body of the Moon was be- 
gun to be obfcured, in a clear Sky 5 (he being then in 
the 2,5th degree of Ubra % and 6° i above the Horizon. 
(Suppofe the Center.) 
At 9 h the whole under-fide of the Moon was eclipfed, 
and about 8 minutes after nine, it was at the height, or 
rather feemed to decreafe. At 9 h £ there was ftill a third 
part of the Moon Eclipfed. (Suppofe of her Circumference,) 
About ten it decreafed apace, and at io h f there was 
but little to be feen : At io h 45* lt was certainly ended, 
the Moon being then about 2z° high. Thus far the Ob- 
ferver. 
The duration oi this Eclipfe is here made from f 38' 
to about 10*45', which agrees within 8 or 10 minutes 
with our Tables, that never err fenfibly in the conti- 
nuance of Eciipfes 5 and fo much ought to. be allowed 
to an Obferver not fufficiently inftruded to diftinguifh 
the Penumbra from the true lhadow, though a (mall Te- 
a % lefcope 
