568 Wisconsin Academy of Sciences, Arts, and Letters. 
each 3 cm. wide and 5 cm. long. The portions of tubing 
between the windows are about 1.1 cm. wide and soldered 
to them inside are semi-cylindrical pieces of brass wire 
Fig. 1.—Plankton bucket showing parts. 
having a diameter of 6 mm. These pieces of brass wire 
strengthen the strips of tubing and receive the screws of the 
side clamps which help to hold the bolting cloth in place 
over the windows. The bottom of the bucket consists of a 
piece of cast bronze which is soldered into the lower end of 
