SURVEY OF THE BRITISH ISLES FOR THE EPOCH JANUARY 1, 1891. 
29 
In determining the total number of stations, it must be remembered that at many 
places, especially in disturbed districts, the instruments were moved from the position 
first chosen, and some or all of the elements were re-determined in a new place. 
In all such cases we have only counted the second position as a separate station if 
all the elements were independently determined at it. 
On the other hand, at a few places stress of weather or other circumstances 
prevented our measuring all the elements. Such places, when distant from other 
stations, are counted separately. 
In 1892 it was found to be desirable, for reasons given below, to repeat at some 
stations the observations made in the earlier survey. 
These are called “ repeat stations,” and are not numbered separately in the lists 
which follow. 
The number of stations allotted to each observer was as follows :— 
Year. 
Observer. 
No. of stations. 
No. of repeat 
stations. 
1889 
Professor Rucker 
35 
Dr. Thorpe 
15 
1890 
Professor Rucker and Dr. Thorpe 
30 
Mr. Gray 
78 
Mr. Briscoe 
56 
1891 
Dr. Thorpe 
34 
Mr. Gray 
115 
Mr. Watson 
90 
1892 
Professor Rucker 
9 
3 
Dr. Thorpe 
22 
3 
Mr. Gray 
91 
8 
]\Ir. Watson 
102 
10 
Total. 
677 
24 
It will thus be seen that in the 1891 survey observations have been made at 701 
places. 
In the 1886 survey we observed at 205 pla-ces, and, adding these to the total of 
the first column in the above Table, we get a grand total of 882 places in the United 
Kingdom at which the magnetic elements have now been determined. 
The following Tables show how the stations were distributed in the principal 
divisions of the kingdom, and also the number of determinations made of the various 
data required for the calculation of the magnetic eiemenrs. 
