530- SEC. 12. APPLIED MECHANICS. 



2167b. Bathometer, for submarine levelling with graphic 

 registration on board the surveying vessel. 



Dr. F. Schopfleuthner, Vienna. 



This instrument is used in submarine levelling, and for the construction of 

 charts of the water-covered portions of the globe. When in use it is attached 

 to the surveying ship by a cable running through an insulated copper tube. 

 It is towed after the ship, and is connected with a registering apparatus on 

 board in such a way that the portion of the sea bottom passed over is 

 represented in profile. The principle on which it acts is that of the equili- 

 brium between a closed volume of air, and the pressure of the column of 

 water resting on it, and the registration is effected by means of an electric 

 telegraph. When it is employed the course of the ship is fixed by the 

 Peraon described above ; in order that the instrument may not be damaged 

 against the rocks on the ground it is provided with a separate horizontal 

 rudder. 



2167c. Apparatus for guarding against the Stranding of 



Ships. Dr. F. Schopfleuthner, Vienna. 



This apparatus is placed on the bow of the ship, or on a steam launch 

 which moves several hundred metres in advance of the ship ; it serves for 

 warning against rocks, sand banks, or steep coasts, and generally is used 

 when in unknown waters. The determination of the sounding is effected by 

 means of a lead which is towed at about a depth of 30 metres under water, 

 and which is connected with a free swinging pendulum in such a way that, as 

 an alteration of the angle between the two, a needle makes contact on the 

 respective side. A tell-tale shows the depth, and by means of a cable con- 

 nected with the ship sets a signal apparatus in action. The latter is only 

 used when the steam launch is sent out in advance. 



2I78be. Russian and Manilla Hemp Ropes, used in 

 shipping, and galvanized iron wire ropes for ships' rigging, &c. 



Thomas fy William Smith. 



Tarred Russian hemp ropes for ships' rigging, running gear, lanyard 

 ropes, towlines, warps, bolt rope for binding sails, and hauling ropes. 



White manilla hemp rope, for towlines, warps, running gear, point line, 

 &c., &c. 



Houseline and marline for serving rigging, signal halyards, log lines, lead 

 lines. 



Galvanized wire rope, for ships rigging, stays, &c., with specimens of the 

 different modes of fitting shrouds and stays with deadeyes, thimbles, and 

 sockets. 



Galvanized hank to run on the stays, different sizes of seizing strand used 

 in fitting wire rigging, lanyard, and shackle thimbles. 



Copper wire rope lightning conductor, fitted with a thimble to pass over the 

 copper rod when driven into masthead. 



2178bea. Specimens of Iron Wire Rope, for ships' 



rigging. New all $ Co. 



2178beb. Case of Samples of Canvas Sail Cloth, 



for naval and commercial purposes. Baxter Brothers. 



2180a. Model of a Propeller for Ships. 



S. F. Pichler, London. 



