94 
MR. A. W. RtiCKER AND DR. T. E. THORPE ON A MAGNETIC 
the forms described on pp. 71-74, in which the results are analysed and the 
corrections for diurnal and secular variation and disturbance are applied. It will 
thus be possible for those who may desire to do so to inspect these, and the data used 
in the preparation of the Tables on pp. 77-80 will be on record, while this paper will, 
we hope, contain sufficient to enable future observers who are not specially interested 
in the details of the calculations and reductions to find the positions where we 
observed, to know when we observed there, and to judge from the final results of the 
general accuracy of the observations. We have followed the plan adopted by 
M. Moujreaux of giving all the facts with respect to each station together, which we 
think the most convenient. Tables are also given on pp. 251-258 in which the final 
results are entered in tabular form for comparison with the values obtained by calcu¬ 
lation from formulae to be hereafter discussed. 
The stations are arranged in the following "order;—Three groups are formed, 
comprising Scotland, England and Wales, and Ireland, this being the chronological 
order of the bulk of the observations in each of these countries. In each group the 
stations are arranged in alphabetical order, and they are numbered continuously 
throughout. These numbers are affixed to the positions of the stations as given on 
Plate 1., which serves as an Index map. 
The Scotch stations, from Aberdeen to Wick, are numbered from 1 to 54, and 
it should be mentioned that the name of a Loch is regarded as determining the initial 
letter. Thus East Loch Tarbert is found under T. 
The English and Welsh stations, including the Isle of Man and the Channel 
Isles, from Aberystwith to Worthing, are numbered from 55 to 156. 
The Irish stations, from Armagh to Wicklow, are numbered from 157 to 200. 
Thus anyone desirous of looking up the observations at a particular place, can 
easily do so from a knowledge of its name, while the stations in any particular district 
can be found in Plate I., and then referred to by means of the corresponding numbers. 
The data given in each case, are as follows ;— 
(1.) The number and name of the station. 
(2.) Date of the observations. 
(3.) Initials of the observer and numbers of the instruments. 
(4.) Latitude and longitude of the station. 
(5.) Verbal description of the station. 
For the Declination we give :— 
(1.) The time from the southing of the sun (S), at which the geographical 
meridian was determined by sun observations, a positive sign indicating the 
afternoon. 
(2.) The G.M.T. of the determination of the magnetic meridian. 
(3.) The observed Declinations with all corrections applied (§). 
(4.) The mean observed Declination reduced to the epoch, Jairuary 1, 1886 (Sq). 
