HOWIETOUN. 1 9 1 



of the overflow course below the whinstone blocks was turfed, as 

 the water rose over it only at intervals, and experience has shown 

 that turf is by far the best and cheapest under those circum- 

 stances. 



The intake to the Howietoun Fishery acts well, and requires 

 little attention. The principle is equally suited to pass 10,000,000 

 cubic feet per diem, as the 1,000,000 which is its daily task. It 

 offers no resistance to fish passing up or down stream if a little 

 waste is passed over it. In fact, it is in itself a very perfect 

 fish-pass ; no young samlets can get through into the water 

 abstracted from the stream. All the conditions the most sanguine 

 member of an English Board of Conservators could suggest are 

 complied with. No canal company or mill-owner can object, as no 

 water is wasted, and but little trouble, time, or wages expended 

 on cleaning. The fall required for clearance is very slight, and 

 the first cost is not excessive. In no other way can anything like 

 the same quantity of water be passed through a hake or grating 

 of the same area, if the bars are not more than an inch apart ; and 

 even with horizontal bars an inch is far too wide, unless the 

 stream is always free from leaves and de'bris, which no stream is. 

 The zinc (No. 15) should last more than one year; but, even if the 

 sheets had to be renewed every spring, no great hardship ensues ; 

 and in winter, when the smolts are not moving much, oak slats 

 could be substituted for the zinc with safety, economy, and 

 advantage, as, with wood, all danger of even a very temporary 

 stoppage through ice is absent. 



The intake acts as follows : The stream is heightened by the 

 wood dam to the height of its top, and rises above it, according to 

 the state of the stream, till in flood it reaches the level of the 

 overflow. Above this it rises very slowly until the maximum is 

 reached. This must never be so high as to flood into the well. 

 The zinc cover to the water-trap passes only screened water, so 

 that no de'bris larger than the perforation of the zinc can pass to 

 the ponds. All leaves and dirt, if the whole stream is taken, rest 

 on the zinc, and, as they collect, the part free for the passage of the 

 water becomes smaller and smaller ; the stream therefore rises on 



