112 



SEASON 1874-75. 



screen, and a wood plug fitted for cleaning (Fig. 56). The filter 

 was charred inside, and painted outside with three coats of red 

 lead ; a light lid of lining, also painted, covered the filter, and 

 two straps of flooring, 3 inches wide, nailed inside, kept the screens 

 from rising, which they had a tendency to do when clogged. 



This floating of the screens was very troublesome at first. The 

 upper screen, or, more likely, No. 2, would clog, and the water flow 

 over on the next. They are about 1 inch below the top edge 

 of the filter. The screen in front of No. 2 now floats and dis- 

 charges most of the ddbris it has 

 collected on to the next. The first 

 seldom rises until No. 3 has clogged, 

 as the weight of the supply falling 

 on it from the spout keeps it to some 

 at. extent in its place, and also cleaner 

 than the lower ones. The simple 

 expedient of nailing the straps (Fig. 55) on the under side of the 

 lid so as to engage the upper edges of the screens overcame this 

 difficulty, and prolific source of dirt and annoyance, the weight 

 of the lid (Fig. 56) being sufficient to overcome the tendency to 



----I'et' -------- 



>t >i 



_i 





FIG. 56 -scale fa. 



float. The screens were first covered with flannel, as recom- 

 mended by Stone. I soon found they required more time and 

 attention than I could afford. Fine wire was substituted, sixty- 

 four threads to the inch ; then coarser wire, thirty-two threads 

 or thereabouts ; afterwards, when a second filter was added 

 above the hatching-house, but below this one, the wire was used 

 as coarse as sixteen threads to the inch. The daily cleaning of 



