new Ne&uue and Gnjters cf Stars . 4.^- 
that portion by a -handle fattened to a place near the eye-glafs,. 
fo as to make it follow me, and perform a kind of very (low 
ofcillations of 12 or 14 degrees in breadth, each taking up 
generally from 4 to 5 minutes of time. At the end of each 
ofcillation I made a fhort memorandum of the objeds 1 chanced 
to fee ; and when a new nebula or clutter of liars' came, iiv my 
way, I made a delineation of the ftars in the field of view, 
both of the finder and of the telefcope, that it might ferve me to 
find them again. This being done, the inftrument was, by means 
of a fine motion under my hands, either lowered or railed 
about 8 or 10 minutes, and another ofcillation was then per- 
formed like the firft. Thus I continued generally for about 
10, 20, or 30 ofcillations, according as circumfrances wouki 
permit ; and the whole of it was then called a Sweeps and as 
fuch numbered and regiflered in my journal. 
When I had completed 41 Sweeps, the difadvantages of this 
method were too evident to proceed any longer. By going 
into the light fo often as was^neceflary to write down my obfer- 
vations, the eye could never return foot) enough to that full 
dilatation of the iris which is abfolutely required for delicate 
obfervations. The difficulty alfo of keeping a proper memo- 
randum of the parts of the heavens which had been examined 
in fo irregular a manner, intermixed with many fhort and long 
flops while I was writing, as well as the fatigue attending the 
motion, upon a not very convenient gallery, with a telefcope 
in my hands of no little weight, efpecially at the extremes of 
the ofcillations, where it made a confiderable arch upwards, 
were fufficient motives to induce me to look out for another 
method of Tweeping. And it is evident, that the places of 
nebulae hitherto determined, which was till the 13th of 'De- 
cember, 1783, mutt be liable to great inaccuracy. 1 therefore 
V 0L0 LXXVI, 
O o o 
began 
