68 NAVAL SCIENCES. 



barrels, and are under the charge of the steward. In merchantmen they 

 are kept in the run, in care of the mate. 



5. Other Necessaries on Shipboard. In men-of-war a special supply 

 of provisions is laid in for the sick, as well as a store of medicines, surgical 

 instruments, &c., under the charge of a head surgeon and several surgeon's 

 mates. A room with windows on the fore part of the upper deck is usually 

 provided in English ships of the line for the reception of the sick, called 

 the sick bay. Large fleets and squadrons have special hospital ships, for 

 the accommodation of the sick whose diseases are dangerous. Merchant- 

 men have no systematic arrangements for the sick, and only East India 

 vessels and the largest packet ships carry a physician. But every captain 

 has a small chest of medicines, with a book of directions for their use, and 

 he thus takes the place of the physician in case of need. 



In long voyages a supply of linen and clothing is taken in, in order to 

 furnish the sailors, if necessary. This, however, depends on the pleasure 

 of the captain, and, strictly speaking, does not belong to the equipment. 



Among important parts of the equipment, we have finally to mention the 

 various instruments and apparatus necessary to direct the course of the 

 ship. The compass resembles the common surveyor's compass, but is hung 

 in a peculiar frame called gimbals, so that the needle and the circle of 

 degrees shall always be as nearly horizontal as possible. The log {pi. 23, 

 fig. 6) serves to measure the velocity of a vessel through the water. It is 

 a three-cornered piece of board called the chip, to which the logline, running 

 upon a reel, is attached by three legs, two of which are knotted through a 

 hole in two corners, while the third draws out at pleasure. When the log 

 is thrown into the water, it stands almost perpendicular, and at that 

 moment a half-minute glass is turned. As soon as the glass has run out, 

 the line, which is marked off into proportional spaces, called knots, and 

 running freely, is suddenly stopped ; the loose leg then draws out, and the 

 log floats flat on the water, and presenting no further resistance is drawn 

 on board ; the number of knots is counted ; and they each being in the 

 same proportion to a mile that a half minute is to an hour (1-120), the 

 velocity of the ship is easily determined. The lead is a heavy weight 

 attached to a line, in order to measure the depth of the sea in certain places. 

 When the lead is to be thrown (fig. 4), the ship is either hove to or her way 

 is slacked, and three men standing on the chain-wales heave out the lead. 

 When the line ceases to run, it shows that the bottom is reached, and the 

 number of fathoms which the line has run off" is then counted. There are also 

 the quadrants and sextants, for taking the altitudes of the sun and stars, and 

 ascertaining the longitude and latitude. With these are included the chrono- 

 meters, some of which keep such good time that they lose scarcely a second 

 in a voyage round the world. Charts, telescopes, barometers, speaking-trum- 

 pets, &c., are among the necessary articles. We may mention, finally, the 

 different kinds of implements employed in various kinds of work on ship- 

 board, such as the axe (pi. 11, fig. 19) ; the hatchet (Jig. 25) ; the horse-bit 

 {fig. 23), for cutting straight grooves : the adze (fig. 24), for cutting curved 

 grooves ; the scraper (fig. 21) and the double-scraper (fig. 22), to clean the 

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