57 
of Edinburgh, Session 1882 - 83 . 
known, but it has also become so stereotyped by constant repetition, 
that it seems to have acquired the stamp of classical antiquity upon 
it, yet one is surprised to find ‘that reference to it in early writers 
is strangely conspicuous by its absence. Our knowledge of the sub- 
ject seems to have lived almost entirely in tradition. 
It is only within the last year that anything like definite attempts 
have been made to test practically and on a large scale the effect of 
oil on the waves of the sea. The first of these experiments were 
made in March last at Peterhead by Mr Shields of Perth, who has 
taken great interest in the matter. Later on in December last he 
made other experiments at the entrance to the Aberdeen harbour. 
The place selected by Mr Shields for the latter experiments was 
within the entrance channel, at a point about 270 yards inside the 
furthest point of the north pier, and at rather more than 700 yards 
outside the entrance to the tidal harbour. The channel is at this 
point somewhat contracted, and has a breadth of about 240 yards. 
To distribute the oil over the water, Mr Shields erected a. hand pump 
on the north pier, and connected it with a pipe 1 inch in diameter, 
which was laid on the bottom of the channel and carried out more 
than half way across it. The oil was pumped through this pipe, 
and escaped near the middle of the channel by three valves and 
roses placed across it 50 feet apart, so as to distribute the oil over 
some breadth. The oil pumped through the pipe rose to the surface 
in small globules and spread itself over the water. The effect was 
very marked and decided. The oil smoothed over the waves and 
prevented the formation of dangerous crests ; the entrance to the 
harbour was thus made much safer for vessels. Mr Shields .deserves 
great credit for these experiments made on so large a scale, and it is 
much to be regretted that this method of calming the waves is not 
less expensive. Each of the experiments' at Aberdeen lasted for one 
hour j the value of the oil used in each was about £20, and though 
the effect remained for an hour after the pump was stopped, yet the 
expense does seem great. I am not aware if any experiments were 
tried to use less oil, but it is evident that it is possible to use too 
much. There is just one quantity which will give the maximum 
effect ; more or less will not do so well. 
Since the experiments at Peterhead and Aberdeen called attention 
anew to the subject, a number of explanations of this peculiar action 
