Appendix A 
ADMINISTRATION-REPORT 1905—06 == Xi == 
English, Irish and Belgian lightships. By means of correspondence with the directors 
of the hydrographical investigations in the different countries, the constant endeavour 
has been made to get all the available hydrographical data sent in to the Bureau. 
In addition to the sections hitherto used in the publication of the material, 
the observations as a result of the resolution of the I.C. of March 1906 (Proces- 
Verbaux Vol. VI, p. 14, Point 3) have been further subjected to elaboration ac- 
cording to the methods of Prof. V. Bsrrxnes, and in making the calculations the 
method worked out by Mr. J. W. Sanpsrrém and Mr. B. Hettanp-Hansen has been 
followed. Mr. Sanpström kindly came to Copenhagen and instructed the depart- 
ment with regard to this matter. The curves of equal depths of the isobaric sur- 
faces are displayed on two plates published in each number of the Bulletin, from 
the second number of the year 1905—06 onwards. 
The mode of publishing the surface-observations has been changed in the 
course of the year, all the correlated observations of temperature and salinity 
determined by titrimetrical methods being now published m extenso in an inde- 
pendent part of the Bulletin (Resolution of the I. C., 21st July 1905, Procès- 
Verbaux Vol. IV, p. 14, Point IV). The publication of these observations has 
caused the previous Part A of the Bulletin to be split up into two divisions, 
one of which contains a list of the stations and meteorological data, the other 
exclusively hydrographical surface-observations. 
Each number of the Bulletin has been extended by 9 charts showing the 
average temperature of the sea-surface in the North Sea for ten day periods (Re- 
solution of the I. C., 21st July 1905, Procés-Verbaux Vol. IV, p. 14, Point Ill). A 
large part of the temperature material used for this purpose has been received 
from the Deutsche Seewarte in Hamburg (Resolution of the I.C., 21st July 1905, 
Procès-Verbaux Vol. IV, p. 14, Point V). 
. The hydrographical department of the Bureau has also been engaged in the 
preparation of charts and sections showing the average salinity of the North Sea 
and neighbouring waters (Resolution of the I. C., 21st July 1905, Proces-Verbaux 
Vol. IV, p. 14, Point Il). The result of the work, 15 charts and plates, with a 
short description of the method, will be found at the end of this Report as 
Appendix A. 
The first step has been taken towards the calculation and representation of 
the mean temperature in the different periods of the year, charts and sections 
of the mean temperature for the month of August having been worked out 
from the observations made in the years 1902—1905, Some preliminary observa- 
