1914] Sumner, et al.: Physical Conditions in San Francisco Bay 7 
The upper portion consists of a heavy brass tube (Up. T.), termin- 
ce 
ating in the “‘stirrup’’ (Str.), which bears the release lugs (FR. L.) and 
the upper valve (Up. V.) This tube contains a heavy sliding rod of 
bronze (Stm.), terminating above in a ring or eye (fg.), to which the 
rope or cable is fastened, and below in a transverse bar, the “‘trip bar”? 
(7. B.), to which is attached the upper section of the long, slender brass 
rod that operates the lower valve. 
The lower portion of the apparatus consists of an inner and outer 
brass tube, between which is a layer of lead, giving the required 
weight. Within the lead, on one side, is a third tube of small diam- 
eter, through which passes the lower section of the slender brass rod, 
above referred to, which connects the trip bar with the lower valve. 
The inner brass tube has an internal diameter of two inches (51 
mm.). When in use it contains a closely fitting tube of pasteboard, 
which has previously been thoroughly soaked in melted paraffin. A 
new pasteboard tube is, of course, inserted with each use of the 
apparatus. This tube is held in position at each end by an annular 
ledge or seat. The lower of these ledges (pl. 13, LZ.) lies just above 
the lower valve, the upper one is situated just below the upper valve. 
The upper ledge is borne on a threaded ring, which may be adjusted 
up or down, in accordance with the exact length of the pasteboard tube. 
The insertion and removal of the pasteboard tubes necessitates the 
uncoupling of the apparatus at the flanges. After removal the tube 
is cut down to the exact length of the sample taken, and a paraffined 
cork is inserted at each end. This first pasteboard tube is then in- 
serted into a slightly larger one for the sake of greater rigidity, and 
enough melted paraffin is poured into each end to cover the corks 
sufficiently. 
The outer brass tube has an external diameter of 35¢ inches (92 
mm.). This tube, with its lead filling, extends upward for a distance 
of 54 inches (137 em.). At its lower end is the “‘valve-housing’’ 
(V. H.), which contains a valve (V.) like that of an ordinary faucet. 
When open, this is transversed by an aperture which is 134 inches 
(44 mm.) in diameter and is of uniform calibre above and _ below, 
without offering any rough edges or other obstacles to the passage of 
the mud. The pasteboard tubes likewise have this same internal 
diameter. 
The valve-housing tapers toward the bottom, terminating in a 
detachable ‘‘shoe’’ (Sh.) bearing a cutting edge for penetrating the 
mud. 
