^ a Mr. Hey’s Account of 
method of afcertaining the courfe and dimenfions of this arch 
would be to obferve fome of the principal conflellations before 
which it paffed, I made fuch remarks as I was able ; and after- 
wards, by the afiiftance of a celeftial globe, while the circum- 
flances were frelh in my memory, I drew up the following 
account of this, and fome other arches which I afterwards 
faw\ 
The arch which I faw fir ft arofe at E. by N. afcending 
through the conftellation Bootes, and having, with refpecl to 
the breadth of the arch, Ar&urus in its center. Its fou them 
edge paffed a little to the north of Caftor in Gemini, and de- 
fended clofe to the ftar Bellatrix in the left fhoulder of Orion. 
It reached the horizon in the W.S.W. point. In this courle it 
paffed about 12 0 to the fouth of the zenith. Its breadth w'as, 
according to the beft judgement I could form, about 9 or 10 
degrees. It remained vilible about 10 or 12 minutes after I 
had firffc difcovered it, and then vanifhed gradually and irre- 
gularly. I obferved no corufcations, nor any motion in this 
arch. 
I had fcarcely travelled a mile farther, when another, and 
ftili more beautiful, arch made its appearance. It arcle a 
point or two nearer the N.E. than the former had done. Its 
fouthern edge paffed up a little to the north of the tail of the 
great Bear, which was then in a vertical pofition. Its northern 
edge appeared at firft a little to the fouth of the polar (far ; 
but, during the continuance of the phenomenon, it gradually 
receded about 10 degrees to the fouth. The arch defended 
about the W.N.W. ; but neither the eaftern nor wedern ex- 
tremities reached the horizon ; each of them ending in a point 
gradually formed a little above the horizon. This arch might 
be about 10 or iz degrees at its vertex. It continued vilible 
1 for 
