TROUT-HATCHERIES 115 



torn beams of the truss, which of course are 40 feet 

 long, may be made of boards six inches wide, and one 

 inch thick, of different lengths, spiked together so that 

 when completed there will be a solid beam 40 feet 

 long, six inches wide and six inches thick. This will 

 often be found cheaper than a solid beam of that size, 

 and just as effective. The top beam of the truss, 

 which is of course very much shorter, may be made 

 of the same material if desired. The stays, however, 

 should be of solid timber, 6 by 8, with two heavy iron 

 stays or rods, bolted both above and below. The stud- 

 ding may be of 2-by-4 lumber, but for the other tim- 

 bers forming the skeleton it would be best to consult 

 a carpenter. The sides may be of what is called 

 Dutch siding. I have found no urgent necessity for 

 air spaces or paper or inside stripping. 



Spring water, when run into a hatching- 

 honse, being warmer in the winter than the sur- 

 rounding atmosphere, will very likely throw off 

 a heavy mist, which will make work in the hatch- 

 ing house disagreeable ; but the mist can be dis- 

 sipated by having three or four ventilators in 

 the apex of the roof. I would not advise venti- 

 lators the entire length of the building, since 

 they allow snow to enter and keep the house un- 

 comfortably cold. 



The house should be liberally provided with 



