732 SKC. 15. GEOGRAPHY. 



Sounding ring and rod, fitted with wire. 

 Sounding weights, J cwt. 

 Dredge, medium size, complete with net. 

 Trawl, with beam and irons. 



Dredge rope, 5 fathoms of 3-inch. 

 2J-inch. 



2-inch. 



Sounding line, o fathoms. 



Accumulators, one set. For easing the strain, upon dredge 

 rope or sounding line, caused by the motion of the ship. 



Gin block, 9-inch, patent. For attaching to accumulators. 



Slip Water Bottle, for obtaining specimen of bottom water, 

 is a brass rod, with three radiating plates to strengthen it and 

 act as a guide for the brass cylinder which encloses the water. 

 At the bottom and half-way down the radiating plates are finely- 

 ground sections of cones, upon which the upper and lower surfaces 

 of the cylinder accurately fit. Over the notch of the tumbler at the 

 top of the brass rod is placed the bight of a line which suspends the 

 cylinder over the cones while the bottle is descending, and which 

 is released by the tumbler falling over, when the strain is removed, 

 by the instrument reaching the bottom, thus allowing the cylinder 

 to fall on the cones and enclose the bottom water. A tap at the 

 bottom of the bottle facilitates withdrawing the water. 



Stop-cock Water Bottle, for obtaining specimens of water 

 at different depths, consists of a brass tube, with stop-cock 

 and bell-shaped mouth at either end. Each stop-cock has a 

 lever attached to the brass side-rod in such a manner that the 

 movement of the rod opens or closes the cocks simultaneously. 

 The brass plate, hinged on a stud near the top of the side-rod, is 

 so arranged that, while the bottle is descending and the water 

 passing freely through, it remains in a vertical position. On the 

 sounding line, to which the bottle is attached, being checked, the 

 plate assumes a horizontal direction, and on heaving up, the pres- 

 sure of the water on the plate closes both stop-cocks ; a still 

 greater pressure is sufficient to release the plate from the spring, 

 which retains it in position when it falls down in a Hue with the 

 side-rod. A small tube, with spiral spring, in the upper part of 

 the bottle, allows the water to expand. 



Tow Net. 



Set of Sieves, for sifting mud dredged from the bottom. 



