170 PHILOSOPHICAL TRANSACTIONS. [aNNO 1787. 



54th and 53d Ursae majoris, and the 14th, 15th and l6th Comae Berenices ; and 

 makes an oblique triangle with them, the vertex of which is turned towards the 

 south. 



Miss Herschel made several observations of this comet, with a Newtonian 

 sweeper of 27 inches focal length, and a power of about 20, the field of view 

 being 2° i 2'; which evinced the comet's motion, by its change of position to certain 

 stars. 



II. Remarks on the New Comet. By IVilliam Herschel, LL. /)., F. R. S. p. 4. 

 As my sister's letter of the 2d of August, relative to the comet discovered by 

 her, has had the honour of being communicated to the r. s., I beg leave to add 

 the following remarks on it. The track of the parallel not being taken at the 

 time of her observations, I have endeavoured to recover it by means of directing 

 the same instrument which was used on this occasion towards that part of the 

 heavens where it was placed the 1 st and 2d of August. Hence, from fig. g, 

 pi. 1, in which ab represents a parallel of declination, we may conclude, that 

 the comet was nearly in the same meridian with the star a ; but more north 

 than it by an interval equal to the distance of the small star b from a. This 

 will consequently give us a pretty good opportunity to ascertain the comet's place 

 with some accuracy. 



p. s. The first view I had of the comet, after my return from Germany, was 

 the igth of August, when with a 10-feet reflector it appeared not much unlike 

 the 3d nebula of the Connoissance des Temps, with which it might be very 

 conveniently compared on account of its proximity. It was however consider- 

 ably brighter, and seemed to have a very imperfect and confused kind of gathered 

 light about the middle, which could hardly deserve the name of a nucleus. It had 

 also, besides a diflfused coma, a very faint, scattered light towards the north 

 following part, extending to about 3 or 4', and losing itself insensibly. 



///. Magnelical Experiments and Observations. Being the Lecture founded by 

 the late Henry Baker, Esq., F. R S. By Mr. T. Cavallo, F. R. S. p. 6. 

 The Bakerian Lecture, which last year I had the honour to deliver to the 

 R. s., contained the account of some magnetical experiments, particularly con- 

 cerning the magnetism of brass, from which it appeared, that most brass becomes 

 magnetic, so far as to attract the magnetic needle, by being hammered, and 

 loses its magnetism by annealing or softening in the fire ; but that there is some 

 brass, which possesses no magnetism naturally, nor acquires any by hammering. 

 Several experiments, made since the reading of that paper, having shown a few 

 particulars, which tend to correct what was advanced in it, I shall in the present 

 lecture mention, first, those particulars, and shall then proceed to notice other 

 experiments and observations relating to other branches of the same subject of 

 magnetism. 



