182 Mr. Wotraston’s Method of defcribing the relative 
But this would be a work of time, and not within the com= 
pafs of every one. What 1 mean now to propofe is more im- 
mediate ; and not out of the reach of any who ammute them- 
felves with viewing the heavenly bodies, . 
Meridian altitudes and tranfits can be taken but once in 24. 
hours; and, though accurate, are therefore tedious. Neither 
can any re-examination of them be made, but with the fame 
Jabour as at the firft. Equatorial fectors are in the hands of 
few; and require great fkill. Some more general method 
feemed wanting; ‘to difcover variations, which, when detected 
or only furmifed, fhould be configned immediately to a more 
{trict inveftigation. 
Turning this in my thoughts, I confidered, that the noting 
down at the time the exact appearance of what one fees, would 
be far more fimple, and fhew any alterations in that appearance 
more readily, than any other method. A Drawing once made 
would remain, and could be confulted at any future period 5 
and if it were drawn at firft with care, a tranfient review 
would difcover to one, whether any fenfible change had taken 
place fince it was laft examined. Catalogues, or verbal Defcrip- 
tions of any kind, could not anfwer that end fo well. 
To do this with eafe and expedition was then the requifite : 
‘and a telefcope with a large field, and fome proper fub-divifions 
in it, to direct the eye and affift the judgement, feemed to bid 
moft fair for fuccefs. 
The following is the method which, after various trials, I 
have adopted, and think I may now venture to recommend. 
To a night-glafs, but of DoLtonp’s improved conftruGtion, 
which magnifies about fix times, and takes in a field of juft 
about as many degrees of a great, circle, I have added crofs 
wires, interfecting each other at an angle of 45°. More wires 
6 may 
