MUSEUM OF COMPARATIVE ZOOLOGY. 177 



This tumbler is kept back by the spring N, and the bail cannot be re- 

 hooked when the line is hauled taut to reel in. 



The resistance of the bottom soil raises the poppet-valve F, and the 

 specimen of soil enters the cylinder, the water within the cylinder being 

 free to escape through the various perforations /*, P, etc. 



On hauling back, the poppet-valve falls, or is forced by its spring, H, 

 to the valve-seat, and the cone falls, closing the water apertures. When 

 the rod has been got on deck the lower part of the cylinder is unscrewed, 

 when the specimen of soil may be extracted. 



The poppet-valve arrangement is Captain Belknap's, but I have taken 

 the liberty of employing it somewhat differently from his method. The 

 water-valve an'angement I have also changed, for certain reasons of con- 

 venience, etc. 



Sigshee Water Specimen Cup. 



Description of Parts. 



The cylinder A. 



The lower valve-seat B, which screws to the cylinder by a right-handed 

 thread. 



The detachable upper-valve seat C, detachable to allow the removal of 

 the upper valve for cleaning. 



The upper and lower poppet-valves D and E, connected by a rod of 

 spring brass wire, and adjustable by a fine screw-thread at F. 



A small brass compression spring at G, to prevent a too easy disadjust- 

 ment of the valves. 



The framework H, fastened to the cylinder with a left-handed screw- 

 thread, enclosing the upper valve-seat. 



The German-silver removable sleeve /. 



The brass pin J. 



The German-silver shaft K, with right-handed screw-thread (44 to the 

 inch) at L and M. 



A German-silver propeller, composed of two bent blades N, N ; the hub 

 ; the inside screw-thread P (44 to the inch) ; the cap Q, remov- 

 able, but fitting tight on the hub ; and the bevelled lugs R, R. 



The German-silver bouching aS*. 



A German-silver screw-cap with milled head, T, T ; bevelled slots, U, U; 

 and inside screw-thread V. 



A clamp composed of the two lugs, W, W ; the pivot screw X ; and the 

 steel spring wire Y. 



