1887.] Dr H. R. Mill on Salinity and Temperature of Firths. 251 
of the distribution of salinity* in the central, southern, and eastern 
parts of that sea. JSTo observations had been made in the great bight 
known as the Moray Rirtli, and this part of the map was accordingly 
left blank. The general distribution of salinity is as follows : — 
Water with more than 3 - 55 per cent, of salts in solution comes in 
from the Atlantic between the Orkney and Shetland Islands * the 
centre of the North Sea is filled with water with over 3 ‘50 per cent, 
of dissolved salts ; while to the south and all round the coasts fresher 
water is found. The line of 3 ‘50 salinity was found to approach 
the Scottish coast at Berwick and again at Peterhead, but between 
these it swept out in a wide curve to the north-east. There were 
no available data by which the German Hydrographic Office could 
determine whether the Moray Firth was in the area of water over 
or under 3 '50 per cent, salinity. 
Dr Macadam in 1866 made some observations in the Moray Firth ; 
Dr J. Gibson in 1883 made a number on behalf of the Fishery 
Board for Scotland;! and in 1885 Mr Ritchie and I examined that 
part of the region about the mouth of the Spey. J In the discussion 
which follows these results are considered, but most of the data used 
are derived from the cruise of the “ Garland” in August 1886. 
Dr Gibson and I proposed to the Fishery Board, in June 1886, 
that they should extend and repeat the physical observations which 
had been already made in the Moray Firth and the smaller sea-inlets 
in connection with it. To this the Board acceded, and we drew up 
a plan for carrying on the work. The steam-tender “ Garland” was 
only available for three weeks from August 1st ; Dr Gibson was 
unable to take part in the expedition, but I was ably assisted by Mr 
F. Maitland Gibson, and, for part of the time, by Mr T. Morton 
Ritchie, B.Sc. 
The methods of working were similar to those which I have pre- 
viously employed and frequently described to the Society. Negretti 
and Zambra thermometers were used, fitted in the Scottish frame, 
and the water-bottle described to the Royal Society in January 1886 § 
* Ergebnisse der Untersiiclmngsfahrten S.M. Knbt. “ I)r ache ” in der Nor dsee 
in deii Sommern 1881, 1882, und 1884. Berlin, 1886. Abstract in Scottish 
Geographical Magazine , August 1887, iii. pp. 385-398. 
t Fourth Annual Report, Fishery Board for Scotland, App. F, No. 12. 
+ Proc. Roy. Soc. Edin ., 1885, xiii. pp. 460-485. 
§ Proc. Roy. Soc. Edin., 1886, xiii. p. 545. 
