612 ; TRANSACTIONS OF SECTION G. 
A tall glass tube filled with water was exhibited; in this bodies of different 
shape were allowed to sink; in every case, whether discs, rectangular plates or 
rods, the bodies settled in the position offering the greatest resistance to move- 
ment. It was shown that this property might result in more rapid settlement 
in running than in still water, and also account for a cleavage in sedimentary 
rocks, 
A model of an instrument for exploring sand-bars and river-beds was shown. 
It consisted of two tubes arranged concentrically, connected at the top, but 
separated at the bottom. A cock-and-hose attachment was fixed on the upper 
end of the inner tube, and a second cock, with a spout, communicated with the 
top of an annular space between the two tubes. At the bottom the inner tube 
ended a short distance above the end of the outer tube. Water, if forced down 
the inner tube, must pass out at the bottom when the cock to the annular space 
is closed; in this case the instrument sinks if placed on a sandy bottom. When 
at any desired depth the cock to the annular space is opened the water returns 
up the outer tube, carrying a sample of the sand with it, and delivering the 
sample from the spout. By means of this instrument the depth and nature of 
bars and shoals may he easily ascertained. 
