C 375 ] 
When a particular Relation of all thefe Obferva- 
tions was read before the Royal Academy of Sciences 
at RariSj and inquired into 5 the main Exception 
taken to them was, That the Obfervers, omitting to 
make a Proof of the Line of Collination, by means 
of double Obfervations, with the Face of their In- 
ftrument turned contrary Ways, have thereby not 
duly afeertained the Tmrh of their Obfervations. 
But this Objeftion was fully anfwered by Monfieur 
MaupertuiSi as Mr. Celfius hopes and believes, to the 
intire Satisfadion of Monfieur Cajfmi., who made it. 
He allows M. Caffini had very good Reafon to men- 
tion this, as a thing proper to be done in Inftruments 
of common Ufe, for this Purpofe, which generally 
Band in need of fuch a Method of Verification : But 
it was not at all neceflary in the Inftrument ufed at 
SCornea and Mount Kittis : The very Make of it was 
fuch, that no Alteration could eafily be made in it,, 
fo as to create any perceptible Error in the Obferva- 
tions. The whole Apparatus of the Telefcope and 
Sedor is all framed together j the Objedrglafs and 
Crofs-wires, as well as the Limb, fo firmly fixed to 
the Tube, as not to be diflocated without great Vio- 
lence. Notwithftanding all this, the utmoft Care 
was taken in tranfporting it from one Place to an- 
other ; being placed in a Cheft, that the LapLanderSy 
to ufe his own Words, in ilia eijia idoluni^ (^uoddam 
fervari facile fbi perfuaderent. He adds, the fame 
Objedion may be made to Monfieur Ricard’s Obfer- 
vations, who does not feem to have ufed this Pre- 
caution, as Monfieur Cajfni himfelf acknowledges, 
who neverthelefs approves and extols his Obferva- 
tions for their Accuracy : So that thofe at the Ardic 
Circle 
