70 



SCIENCE. 



[Vol. IL, No. 24. 



holds, storerooms, and open decks, having its 

 share. They are couti'olled by a Z dynamo, 

 driven by an Armington and Sim's liigh-speed 

 engine. An arc-lamp of great power, designed 

 b3' Dr. O. A. Moses, and intended for illumi- 

 nating the surface of the water, works in cir- 

 cuit with the same system ; and there is also a 

 powerful submarine lamp which can be lowered 

 to any depth not exceeding a thousand feet. 

 This latter feature is quite nov- 

 el, and is to be used to attract 

 schools of fish and other free 

 swimmers, should its strong 

 rays of light possess the in- 

 fluence which the}' are sup- 

 posed to have. 



The sounding and 



dredging appliances 



and working-gear 



supplied to 



the Alba- 



t r o s s 



are mainty patterned after those which have 

 been successfully' introduced bj^theU. S. coast- 

 surve^' and fish-commission in recent years. 

 All sounding operations are to be con- 

 ducted with steel piano-wire of No. 21 Ameri- 

 can gauge, on the system of Sir William 

 Thomson, for which purpose two styles of 

 sounding-machines are furnished. One of 

 these is the invention of Commander Sigsbee, 

 U.S.N. , and the other of Lieut. -Commander 

 Tanner, U.S.N. The Tanner machine, in 



which the reeling-in is accomplished by hand, 

 is extremely simple in its workings, and is in- 

 tended for moderate depths of water only. It 

 is attached to the rail on the port side of the 

 main deck, forward of the pilot-house. The 

 Sigsbee machine can be used in all depths of 

 water, down to the deepest parts of the oce^an, 

 and is worked b}' steam. It occupies a promi- 

 nent position on the port side of the top-gallant 

 forecastle deck (see opposite page). The 

 principal accessories to sounding are the Sigs- 

 bee sounding-rod, with detachable weights ; 

 the Sigsbee water-cup ; and the Xegretti and 

 Zambra deep-sea thermometer, with a new 

 stj-le of reversible metal case recenth' devised 

 by Messrs. Bailie and Tanner of the fish-com- 

 mission. With these appliances, samples of 

 the bottom formation and water, and the tem- 

 perature of the latter, can be obtained at each 

 cast of the lead ; and, b}- using a heavier 

 souuding-wire (No. 18 wire gauge), several in- 

 termediate samples and temperatures are also 

 procurable without much additional trouble. 



The dredging appliances are as nearly per- 

 fect as are those for sounding, and comprise 

 everj' improvement which has been hitherto 

 suggested. Steel-wire dredge-rope meas- 

 uring onlj- an inch and an eighth 

 in circumference replaces the old 

 le of three-inch hempen rope, 

 hich is no longer recognized by 

 deep-sea dredgers on this side of the 

 antic. The principal advantages 

 wire rope are its compactness, 

 strength, and durability, and the 

 ease and speed with which it can 

 be handled. The working-reel of 

 the Albatross, on which -1,000 

 fathoms can be stored at a 

 time, occupies so small a space 

 on the ship that its presence 

 is scarcely noticeable. 



The dredging machinerj- con- 

 sists of a powerful hoisting-en- 

 gine on the main deck directh- 

 in front of the foremast, and a reeling-engine 

 and reel on the berth- deck underneath. A 

 strong dredging-boom, thirty-six feet long, 

 and pivoted to the foremast about seven feet 

 above the deck, carries the dredge-rope clear of 

 the vessel, and can be raised and lowered, or 

 bent aside at anj" angle, to suit the convenience 

 while dredging or trawling. Sudden strains 

 on the dredge-rope are relieved bj- a Sigsbee 

 accumulator, consisting of about thirty-five 

 rubber car-buffers arranged for compression 

 on an iron- rod. This important accessor^' 

 hangs suspended from the masthead above the 



