50 ANNUAL OF SCIENTIFIC DISCOVERY. 



of the man who steered her, tacking and veering about, none the 

 worse for her fluid cargo." 



SECTIONAL BOATS. 



A NOVEL description of boat has just been completed at Liverpool, 

 for the use of her Majesty's Consul at Fernando Po, on the West 

 Coast of Africa. This boat is the invention of Mr. Macgregor Laird. 

 The peculiarity of construction consists in her being built in sections, 

 which can be put together, and made perfectly secure, without me- 

 chanical or skilled labor. The official report from Commander Bevis, 

 R. N., to the Secretary of the Admiralty, states her dimensions and 

 efficiency as follows: Length, 68 ft. ; beam, 12 ft.; depth amid- 

 ships, 4 ft. ; forward and aft, 6 ft. ; tonnage, builder's measurement, 

 45 tons ; total weight of iron-work, 4h tons ; weight with wood-work, 

 masts, sails, rigging, anchors, cables, and all complete, 8 tons. Dis- 

 placement at 2 ft. draught of water, 20.89 tons. There are eight sec- 

 tional pieces, the heaviest of which is 16 cwt., joined together 

 by angle-iron joints, lined with vulcanized India-rubber ; the whole 

 being secured by screw-bolts and nuts, so that her own crew, of forty- 

 five or fifty men, can carry her over any neck of land and set her 

 up again. "Her light draft of water is estimated at one foot, with 

 her crew; with provisions, water, &c., for the same, at two feet. 

 She is to pull thirty-eight oars, double-banked, fitted with three 

 schooner-sails and square-sail, having, for night protection, iron stan- 

 chions covered with thin felt. She is also to be fitted with air-tight 

 galvanized tubes as a life-boat. From her light draught of water, and 

 general lightness, she is particularly well adapted for crossing the 

 bars on the coast of Africa, where there is a short breaking sea ; and 

 for proceeding up the rivers, or to go in chase of slavers, as, from her 

 construction, she must pull and sail very fast." The Superintendent 

 of Emigration at Liverpool recommends similar boats for emigrant 

 ships. London paper. 



NEW SOUNDING-LINE. 



THERE has been lately deposited in the Naval Museum at Paris, the 

 model of an ingenious sounding apparatus, invented by M. le Coentre, 

 who in 1841 commenced a series of experiments on board the Africaine 

 frigate for testing the accuracy of his invention, which the several re- 

 ports of the officers concur in stating to be complete. This new 

 sounding-line consists of a hollow truncated cone, of copper bronze, 

 ID! inches in height, about 6 inches in diameter at the base, and 2 

 inches at the summit. The metal is very thick, and upon one of the 

 sides is placed a strip of glass, enabling the observer to read the scale, 

 which is 11| inches in length. An endless screw, which is the axis 

 of the cone, acts upon an index, or traverser. The screw passes 

 through the upper part of the cone ; and to the protruding portion, or 

 shoulder, are attached two little wings, or fins, perpendicular to each 

 other. Their inclination varies according as it is desired to obtain 



