ON THE MAEINE BIOLOGICAL STATION AT GRANTON, SCOTLAND. 253 



Physical marine research has from the commencement formed one of the 

 distinctive features of the Scottish Marine Station. During last year 

 work has been carried on in this direction by Dr. H. R. Mill and ]\Ir. J. 

 T. Morrison ; other gentlemen have occasionally made nse of the facilities 

 of the Station. 



Regular meteorological observations are continued twice daily, and in- 

 clude the temperature at surface and bottom of the water. An elaborate 

 set of experiments with Mr. John Aitkin's new forms of thermometer 

 screen were completed last year by Mr. H. N. Dickson. Experiments 

 witb various anemometers are still in progress. 



Atmospheric dust is being collected on several islands in the Firth of 

 Forth by means of large funnels and carboys, which are periodically 

 emptied and the contents forwarded to Mr. Murray for examina- 

 tion. 



Monthly trips along the Firth of Forth for the observation of tempera- 

 ture and salinity have taken place regularly from river to sea ; prelimi- 

 nary results have been communicated to the Royal Society of Edin- 

 burgh from time to time, and a cotnplete discussion of salinity is nearly 

 ready for publication. It shows remarkable relationships between salinity 

 and configuration, which have suggested new definitions of the words 

 river, estuary, and firth. Special attention has been devoted to the relation 

 of salinity and temperature to tide in the estuary of the Forth. Besides the 

 observations of the scientific staff of the Station, thermometer readings are 

 taken by volunteer observers at different parts of the Forth river-system 

 and in the adjacent parts of the North Sea. 



The Medusa has made regular trips on the Clyde since April last at 

 intervals of two months. Temperature and salinity observations are made 

 in all parts of the estuary and firth from Dumbarton to the North Channel, 

 and in all the connected lochs. These trips have yielded results of great 

 interest and novelty. They are communicated in several papers to various 

 sections of the present meeting. 



The temperature of two deep fresh- water lakes — Locli Lomond and 

 Loch Katrine — has been observed at all depths once a month since Novem- 

 ber 1885, in continuation of Mr. J. Y. Buchanan's work. 



Daily temperature observations have been established on a number of 

 rivers and at several points on some. The Station has charge of obser- 

 vations on the Thurso, in the north of Scotland, the Forth and Teith, and 

 the Tweed ; and it has also been the means of inducing independent ob- 

 servers to undertake similar work on the Tummel (a tributary of the 

 Tay), the Tay, and the Derwent, in Cumberland. These are all salmon 

 rivers, and the observers being interested in fishing have already suc- 

 ceeded in showing some connection between temperature and the move- 

 ments of salmon. 



In consequence of experience gained in physical marine investigations 

 the apparatus used for the purpose has been progressively modified and 

 improved — the Scottish thermometer- frame and water-bottle may be 

 pointed to as special instances. 



The Station has, since September 1885, been able to advise and assist 

 several public bodies in starting observations of temperature and salinity, 

 the National Fish Culture Association of England, the Dundee Harbour 

 Trust, and the Fishery Board for Scotland being amongst the number. 

 Thermometers have been lent to several naturalists for nse on short 

 scientific voyages. 



