[ 4 * 1 
the moft Southern, has no others Bounds to the Eaft 
than the Eaft itfelf, if I may be indulged the Expref- 
fion 5 feeing its Extent that Way contains near half 
the Earth f 
Another great Advantage to be obtain’d by the ' 
Work I now propofe to be made in RuJJla , is. That, 
we coming after others, fhall reap the Benefit of all 
their Knowledge and Experience in the like kind of 
Meafurements : Whence we may exped to fucceed 
and execute it better than could have been done elfe- 
where, by applying timely Remedies againft the Diffi- 
culties that occult d in other Places. 
Thefe Operations are to be founded on a Balls of 
the greateft Length poffible ; which muft be adually 
meafured, and with the greateft Exadnefs that may 
be 5 as it is to ferve for a Foundation to the Meafure- 
rnent of all the Triangles. And in this Point too we 
have a very great Conveniency near Retersbourg , fee- 
ing on the Ice here we may meafure out a Bafis, 
greater than has been hitherto taken, namely, from 
the Coaft of Ingria about Reterhojf y to the Coaft of 
Finland toward Syfterbeck . There is not lefs than 
20 Werfts Diftance between thefe two Extremities, 
and this great Diftance may be meafured very exadly, 
this Year efpecially, that the Ice is very even. More- 
over, as this Bafis is fituate between the Ifle of Cron - 
Jlad and Retersbourg , in a Diredion nearly perpen- 
dicular to the Diftance from Retersbourg to Cron- 
fiady there can be no better Method for inferring 
thence, by exad Obfervation of the Angles taken at 
the Extremities of this Bafis, the Diftance from the 
Centre of the Imperial Obfervatory to the Steeple of 
the new Church of Cronftadi which two Objeds 
are feen reciprocally from each other, and are not 
Ids 
