304. EXAMINATION OF THE PRESENT STATE 
equal to the emergency by devising an air-circulation. The device 
has been arrived at, I believe, quite independently, although the 
principle of an air-circulation has long been familiar to those interested 
in aquaria, and we have here an instance of a case in which the 
“ practical’? man might have saved himself much expenditure of 
ingenuity by a little attention to what is being done by his scientific 
brethren. It may be urged, perhaps, with equal truth that the 
biologist should have perceived the opportunity of an economic im- 
provement, and I have to confess that the idea of adapting an air- 
circulation to a ship’s well did not occur to me until last spring, 
when | had occasion to fit such a circulation to the Cleethorpes tanks. 
On communicating my ideas to a smack-owner I found that he was at 
that time actually engaged in patenting an apparatus essentially 
similar, but devised entirely by himself and friends. 
The preceding remarks will perhaps suffice for our purpose, 
without entering into a long technical description of the various 
classes of fishing vessel. Indeed, such is hardly necessary, as Pro- 
fessor M‘Intosh has recently published in the Association’s Journal 
a detailed account of Scotch steam-trawling vessels, and the later 
types of these agree with the Grimsby boats in all essential details. 
It may be remarked, however, that a deck-house is confined to 
Aberdeen boats, and no English trawlers that I know of carry an 
otter-trawl. 
Grimsby steam-trawlers are divided into two classes. ‘Those 
ranging from 35 to 40 tons nett register are spoken of as ‘ inshore ” 
boats, though it must not be supposed they work what are, strictly 
speaking, inshore grounds. These boats carry a 50-foot beam-trawl 
and 200 fathoms of warp. The larger steam-trawlers range from 50 to 
70 tons, and carry a 56-foot beam and 250 fathoms of warp. ‘The 
bridles in both cases are 26 feet long. 
The smaller trawl-smacks carry a beam of 44 feet, and 140 
fathoms of warp. The larger ones have the beam 50 feet long, and 
180 fathoms of warp. The warp of a steam-trawler is of wire, 
smacks using warps of manilla rope. 
The sailing trawlers at Grimsby and Hull are fast being super- 
seded by the steamers. The latter increase every year, while the 
former are gradually disappearing, those which succumb to wreck or 
old age being seldom replaced by new ones. At Boston the deep- 
sea trawling industry was started by steamers, and has never been 
carried on by smacks at all. 
At Lowestoft it appears that steam-trawling has been considered 
unsuitable, and that the smacks are increasing. Moreover, at this 
port a class of vessel smaller than that generally im use at the 
Northern ports finds most favour, and the modern type of smack 
