t 3 
In like manner, in any other Cafe where z and z are two Abfciffes 
whofe Difference as a Meafure is z; and y, y the two Ordinates; 
the Magnitude of the Figure will be implied by the Magnitudes of the 
two Polygons which are made from the Sum of the infcribing and 
circumfcribing Elements zy and zy, although the Figure itfelf is not 
to be refolved into any fuch primogenial rectangular £lements. 
And thus, I think, the Symbol z, confideredas a component Part 
of the ReCtangle z y , may bear a plain Interpretation ; viz. that it 
is the Meafure according to which the Quantity z is meafured; nor 
can I fee that any other Interpretation need to be put upon a Symbol, 
which, like a Meafure, is ufed only to make other things known, but 
•is of itfelf for nothing but a Mark. 
And what is faid of the Elements of the firft Refolution, is eafily 
applied to thofeof a fecond or third, and fo on; the laft may always 
be confidered as the Meafure of the former and indivifible, although, 
in refpedt of the following, it be taken as the Part according to which 
: the Meafure was made, and. therefore divifible. 
'The candid Reader is defited to fir ike out a Remark -of mine , about 
the Comet of 1556, fuhjoined to an Obfervation of the late Comet 
made at Lisbon, printed in Rage 123 of the lafi TranfaCtions, N Q 446. 
The Note was there infer tod i>y fome Accident, without my Intention 
for I had foon afterwards informed the Society, that the Remark was 
ill-founded. According to Mr. Bradley’* Obfervations at Oxford, 
which were not then commu?iicated , the Rlace at the Time mentioned 
ought to have been in Long. X. 13 0 . 21'. 5 . Lat. o°. 29/. South. 
So that in all probability there happened fome Mi fake in making this 
Obfervation. 
ERRATA. P. 213. L. 31. for n.n — 2 read n.n — 2. 
J?. 222. L. 2 6. for being read be. 
Printed for T. Woodward, at the Half-Moon, 
between the Two Temple-Gates in Fleetjlreet > 
and C. Davis, the Corner of ‘Pater-nojler-row , 
next Warwick-lane-, Printers to the Royal 
Society. M.dcg.xxxix, 
