S64 Hansteen's Chari of the Variation and Dip of the Needle. 
tioned ; but the Eastern line differs in a very remarkable man- 
ner from the same line in Churchman. 
In Hansteen’s chart, the Eastern line of no variation passes 
through New Holland to Archangel, after making numerous 
inflexions among the Indian Islands, and through the continent 
of Asia ; while Churchman gives it nearly a rectilineal course 
from New Holland to a little beyond Enisesk in Siberia, where 
he makes it terminate. In the chart of Hansteen, the lines of 
eastern variation from 0° to 10°, partake of course of the sinu- 
osities of the line of no variation ; but though they resume a 
more uniform course to the west, yet in the Pacific Ocean they 
form a series of returning curves of the shape of a heart, which 
have no resemblance to those in Churchman‘’s chart. 
In examining the different groups of the Variation Lines ^ 
the reader will observe that they are represented on the en- 
graving by three different kinds of lines. The lines marked 
thus, — - continuously black, are the lines which are best 
determined. Those marked thus, — . . . — have an infe- 
rior degree'of evidence; while those marked by a single dotted line 
thus, are merely interpolated by estimation. The 
same remarks apply to the Lmes of Dip, where, however, only 
the continuous and the dotted lines are used. Lines of 
and 75° of North Dip, for example, are entirely interpolated ; 
and also the Asiatic portion of the lines of 60° and 70° of North 
Dip, and the Atlantic portion of 60° of South Dip. 
In the present chart, we have added the new discoveries of 
Captain Parry, and New Shetland ; and also one or two points 
of variation in Baffin’s Bay, together with the Poles of maximum 
Cold, which we have recently deduced from a comparison of me- 
teorological observations 
D. B. 
Edinburgh, ) 
March 1. 18S1. j 
* See Transactions of the Royal Society of Edmbtcrgh, "vol. ix. p. 214. ; and 
the present volume of this Journal, p. 193, 194. 
