of the Fishery Board for Scotland. 



109 



on the beach itself, being of fireclay pipes, which have answered very well, 

 and have only given rise to trouble on one occasion, in the course of last 

 spring, when a section had to be renewed. The end of the inflow consists 

 of a length of an iron pipe, terminated by an upturned part, raised about 

 two feet from the bottom, and covered with a large shield of wire-netting. 

 This arrangement is to prevent the access of sand, debris, and weeds as far 

 as possible. The outflowing water escapes by a flap-valve at the end of 

 the pipe, beneath the up-turned portion, and on the same level as the rest 

 of the pipe. 



The water on entering goes into a small compartment of the pond called 

 the filter chamber. Here it passes up through wire-netting, which may 

 be of any dimension of mesh, and, if necessary, through filtering materi al 

 There are two slide-valves, one controlling the connection of the filtering 

 chamber with the sea and the other the connection between the chamber 

 and the pond. The water may be admitted direct to the pond, or it may 

 be pumped from the filter chamber to the reservoir tank. 



The latter (a, fig. 1, pi. "VI.) is built of concrete on a natural mound 

 lying between the new site and the spawning pond. It is a strong tank, 

 29 feet long, 7 feet high, and 20 feet in breadth, and capable of holding 

 15,570 gallons of water. It is from it that the supply to the hatching 

 apparatus and to the tanks in connection with the laboratory is obtained 

 during the night. It can be filled by the pumps in about two hours and 

 a quarter. A pipe, carried through the concrete wall at the bottom, 

 leads the water to the hatchery; another carries a supply to the tank-house 

 for laboratory work, and another allows it to pass into the spawning pond. 

 The pipe going to the tank-house is shown in fig. 2, pi. VI., at e, and the 

 pipe entering the pond is on the left of the letter e, and close to it. The 

 water from the reservoir may be filtered or unfiltered ; the iron pipe 

 which passes through the wall of the tank is connected with a flexible 

 hose, the end of which enters a floating box, so arranged that the supply 

 is drawn from the surface, where there is less matter in suspension, and 

 through flannel or other material. 



The hatching-house, as now arranged, measures 49 1 feet in length by 

 24 feet in breadth, part of it being 28 feet wide. The height of the 

 building is 18 feet; it is lighted by 16 windows, and is painted inside in 

 light tints, the walls being pale green and^the ceiling white (fig. 1, pi. VII.). 



Two material improvements were made in the re-erection of the build- 

 ing. A concrete floor, suitably sloped, replaces the previous wooden floor, 

 and is a great advantage, since the water which is spilled over the floor 

 when the work is going on now flows away into convenient gutters, which 

 are connected with the drain going to the beach. The hatchery is much 

 drier now, and the appearance improved. A large sink, supplied with 

 fresh or sea water, has been erected in the middle of the floor for washing 

 hatching boxes, &c. The other chief improvement consisted in taking in 

 the filtering apparatus, which were previously outside, and this was effected 

 by extending the walls and roof, the gable being put further out. For the 

 "tumbling-boxes," which impart automatically a certain movement to the 

 hatchiug boxes, two brick chambers have been built below the concrete 

 floor, each 4 feet 4 inches by 4 feet 8 inches, and 3| feet in depth. One 

 is in connection with the waste water from each side of the hatchery, that 

 is, the water which leaves the hatching boxes and is carried to the pond. 



The filters consist of one large box, 8 feet by 4 feet and by 2 feet deep, 

 and several smaller boxes, which receive the water from the larger one. 

 All these are fitted with filters of flannel or blanketing, on frames covered 

 with wire-netting and made tight by rubber bands ; all the water which 

 comes from the reservoir must pass up through them by pressure, and it 



