

THE SCREW-PROPELLER. 



203 



the cylinder, one end of which is filed to a blunt point. A cir- 

 cular disc of thin brass is now prepared, having a diameter which is 

 |mm i ess than the internal width of the glass cylinder at a, fig. 146 

 .1, and a hole is drilled in the middle, into which the steel wire fits 

 rather tight ; the hole should therefore be made at first too narrow, 

 and then cautiously widened with the rimer. The disc should be 

 soldered to the wire so as to be at a in the cylinder when the point 

 of the wire rests in the cavity of strip 6, From six points of the 



FIG. 146 (A and C, an. proj. | real size ; B f real size). 



edge equally distant from one another, cuts are made with the 

 shears to about l mn .5 f rom the spindle, as shown in fig. 146 J5 ; 

 six blades are thus formed, which are bent with the flat pliers into 

 the oblique positions shown at 146 A. The hole cc in the cross- 

 strip at the top should be widened with the rimer so as to allow 

 the spindle just to pass easily through it, but not too loosely. 

 The screw is placed within the cylinder, and the ring with 

 the cross-strip upon the top of it ; the whole is clasped in 

 some convenient way, the hole in the cork is closed with the 



