478 REPORT— 1885. 
different places. A new mechanical arrangement for inverting the 
Negretti & Zambra self-registering thermometer was invented soon after 
the work was begun; the original arrangement was found to be unsuit- 
able for work on board a small steamer in shallow water where the 
currents were rapid. In the new frame the inversion is effected by the 
fall of a messenger along the line upon a horizontal lever. The mechanism 
was explained by Mr. Mill, in a paper communicated to the Royal Society 
of Edinburgh in July 1884. For taking samples of water at different 
depths, a modification of Mr. Buchanan’s slip-water bottle is used. The 
alteration consists in the fact that the slip cylinder, instead of being allowed 
to run down the line from the hand of the observer, is suspended just above 
the frame by a spring lock, and is released by the fall of a messenger sent 
down from the deck of the ship. 
In the summer of 1884 an inquiry was made, by means of a number of 
series of observations at short intervals, into the tidal variation of tempera- 
ture in the Granton Quarry. The result was communicated to the Royal 
Society of Edinburgh. The temperature and salinity variations in the Firth 
were investigated by means of trips on the Medusa up and down and 
across the Firth. The results of the work are published in a paper 
entitled ‘ On the Salinity of the Firth of Forth,’ ‘ Proc. Roy. Soc. Edin.,’ 
vol. xiii. On various occasions when the yacht has visited the Clyde 
observations have been made on the temperature and salinity of that 
estuary. Some observations have also been made into the physical con- — 
ditions of the Tay and the Tweed. During the present summer, the 
months of July and August have been spent by Mr. Mill in similar work 
at the mouth of the River Spey. <A réswmé of the work which he has 
so far accomplished in investigating the physical conditions of Scottish 
estuaries is to be read by Mr. Mill before the present meeting of the 
Association. 
In July of the present year a very thorough investigation was made 
at the Station, by Mr. H. N. Dickson, of the properties of a number of 
new thermometer screens invented by Mr. John Aitken, of Darroch. The 
aim of the inventor was to devise some form of apparatus which should 
eliminate the causes of error present in the ordinary Stevenson screen, 
now in general use for meteorological observation. Mr. Dickson gave 
an account of his researches to the Scottish Meteorological Society, and 
also to the Royal Society of Edinburgh. Some of the instruments have 
been taken to the Ben Nevis Observatory, where their investigation is 
being continued under different conditions. 
The Marine Station is one of the regular observing stations of the 
Scottish Meteorological Society ; the ordinary observations on the air 
and the temperature at the surface and bottom of the quarry are recorded — 
twice daily, and the records forwarded to the society’s secretary. 
J. T. CUNNINGHAM, 
The Committee beg to recommend the renewal of the grant (100/.) 
for the ensuing year. 
