14 Dr Collation's Narrative of a Descent in the Diving-Bell. 
the shock of an earthquake. A certain depth of water is ne- 
cessary for safety. Mr Bald supposes at least twelve feet. 
The workmen cannot go down and work when the sea is 
very rough, as the swell would prevent them from settling 
on the bottom ; and they are frequently annoyed with what is 
termed a ground-swell , when it is quite still at top. This is a 
sure prelude of a breeze of eastern wind, which seldom fails to 
set in soon after, if it has not prevailed at the time on the other 
side of the channel. 
The best and easiest time for going down is at low water, 
when there is less pressure ; but amateurs prefer going down at 
high-water, that they may have it to say that they were twenty 
or thirty feet below water in a diving-bell. 
The workmen are generally down in the diving-bell five 
hours in the day, without coming up ; and in summer, one set 
of men are down ten hours one day, and five hours the other, 
and so on alternately. They work at all seasons of the year, 
and do not feel much difference in the temperature. The wa- 
ter is more chilly in the winter ; and when they come up into 
the atmospheric air, they feel it rather cold, after being heated 
by their exertions below. They do not complain in general of 
pains in the head, except those that are new hands, who are ra- 
ther affected in that way, and about the ears ; but this affection 
soon wears off. 
They are in general rather relaxed in their bowels, which I 
suppose, is owing to their feet being constantly wet and cold. 
One of the men was verv much affected with a bowel complaint 
this season, which increased as often as he went down. When 
Mr Souter descends, he is generally afflicted with a looseness : 
he has a copious flow of urine, and his appetite is very much 
increased. He always finds it a good plan to take a little spi- 
rits on coming up. The time never seems long to him when 
below ; and he has been several times seven hours under water, 
without ascending, and scarcely thought it half that time. 
None of the men become deaf, and it may be thought that in 
some cases it would be a cure for that malady. 
They once had a man, as Mr Souter informed me, that was 
rather affected in his breathing, but when he commenced helling , 
it completely cured him. 
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