38 ON THE ORBIT-ELEMENTS OF COMET 1., 1880. 
On looking down the list one cannot fail to recognize the close 
resemblance between the elements which I present to the Society 
and the third orbit calculated by Laugier and Mauvais. Butl 
wish also to draw the attention of the Society to the fact that 
these computers assign a period of thirty-five years in their or 
which so closely resembles mine, and this period it will be observed 
differs only two years from the interval between the appearance of 
the comet of 1843 and that of 1880. To their second orbit they 
assign a period of 175 years, and this it will be seen is commenst- 
rate with that of thirty-five years. Mr. Hind, in his Treatise onthe 
Comets, edition of 1852, says :—“ Several comets have been men 
tioned as probably identical with the great one of 1843, and m 
particular those of 1668 and 1689, which exhibited tails of unusual 
len, it were one and the same comet that appeared in 1668, 
1689, and 1843, the period of revolution could differ but little from | 
good grounds for believing that its whole course cannot be Mt 
ce 4 
March and h " mo year, ViZ., on ie 
arch and the following days. Its brightness was SUC) yg 
reflected trace was easily distinguished on the sea be ce 
when it at length came in sight, was comparatively ne eo i 
