412 MEM O IR S of the 
quantity of light illuminating an opaque body, to examine at 
what diftanccs the moon muft be from the earth to lufFer eclipfes 
of the obferved duration. 
ST^e 7ulian Account not to he changed for the Gregorian 5 
by Dr. J. Wallis. Phil. Trani: N° 257. p. 343. 
THE Dr. does not deny but that there is fomewhat of difbr- 
der in our eccleiiaftical computation of the palchal tables 5 
but at the fame time he is very doubtful, that if we go to alter 
that, it will be attended with greater mifchief than the prefent 
inconveniency : In the bufinefs of geography, by removing upon 
Ibme plaufible pretence, the firft meridian from where Ptolemy 
had placed it, tho' a thing at firft purely arbitrary, it is now come 
to pals that we have, in a manner, no firft meridian at all 5 every 
new map-maker placing his firfl meridian where he pleafes, 
which has brought great confufion into geography: As to the 
dilorder in the palchal tables it was a thing oblerved and com- 
plained offer 3 or 400 years, before pope Gregory unhappily at- 
tempted the corredion of the calendar 5 but it was all that time 
thought adviieable to lufftr that inconveniency, rather than by 
correding it to run the hazard of a greater mifchief^ and it had 
been much better i{ it had lb continued to this day, rather than 
that pope Gregory fhould, upon his own fingle authority, im- 
pofe a law on all Chriftendom to alter their eccclefiaitical and 
civil year for a worfe form, than what they had before : Or, 
if merely upon account of the pafchal tables, which was his 
only pretence, it were thought neceflary to make a change, he 
might have corrected them, or given us new pafchal tables 
inftead of thofe of jDionyfms^ without altering the civil year, 
which has introduced the confufion of the old and new ftiles 5 
and which now can never be remedied, unlefs all nations fhould 
at once agree upon one, which is not to be fuppofed 5 for if lome 
iliould alter their flile fooner and Ibme later, the confufion. in 
hiftory would be Hill greater than now it is. The Dr. takes 
the civil Julian year to be preferable to the Gregorian j the 
preceffion of the equinox for 10 or 12 minutes each year, is a 
very inconfiderable matter, and in celeftial computations is 
eafily rectified, as are many other unequalities of much greater 
concernment: And it was never pretended that the civil year 
muft needs agree exaaiy to a minute with the celeftial, which 
IS impoffible u for the folar and fidereal years differ more from 
j^S^ ^^'J.^*"' ^h^» the Julian, which is a mean between them, 
diflrers from eitherj and the feat of Bafier, which only con- 
cerns 
