Juday—Limnological Apparatus . 
569 
the tubing flush with the bottom of the windows. It slopes 
toward the center where there is an outlet tube about 2.3 
cm. long. The upper diameter of this outlet is 1.2 cm., and 
the lower 1 cm., and its walls are a little more than a milli¬ 
meter thick. The outlet is closed by a brass plug, the handle 
of which terminates in a milled head almost flush with the 
top of the bucket so that the plug can be readily removed. 
(Fig. 1, F.) 
The bolting cloth which covers the windows is held in 
place by four brass strips which are as long as the windows 
and as wide as the tubing between the windows. (See fig. 
1, G.) Each of these strips is attached to the bucket by 
three screws. At the top and bottom of the windows the 
bolting cloth is held in place by semi-circular bronze clamps 
about 8 mm. wide, which have wings at their ends for the 
screws which hold the two halves of the clamp together. 
In this type of bucket it requires only a few minutes to 
renew the bolting cloth strainer. The new cloth is cut a little 
wider than necessary so that a free edge projects beyond 
the upper and lower clamps. It is wrapped around the 
bucket and the clamps at the top and bottom are adjusted, 
loosely at first, so that the cloth can be shifted into position. 
Then holes for the screws of the binding strips between the 
windows are burned with a hot wire and the strips are 
screwed on. Lastly the clamps are adjusted so that they 
are flush with the upper and lower edges of the windows 
and then they are drawn tight by means of the screws. The 
bolting cloth projecting beyond them is cut off with the 
point of a kiiife. The ends of the bolting cloth should over¬ 
lap on one of the strips of tubing between the windows. 
THE SMALL NET. 
The small net consists of a truncated canvas cone about 
12 cm. high and a bolting cloth cone about 30 cm. long 
(Plate XXXVI, fig. 1). The framework of the canvas cone is 
shown in fig. 2. It is made of brass wire 4 mm. in diameter 
and consists of an upper ring 12 cm. in diameter, a lower 
ring 18 cm. in diameter, and three connecting rods. The 
latter have loops at their ends and are fastened to the rings 
by means of pieces of smaller brass wire bent into the shape 
of a figure eight. These connecting loops fit loosely onto 
