. Archives of useful knowledge. liable to some additionalpull from being exposed to the wind. To this inconvenience, thelog line in the common way of heaving the log is hkewise expos*ed when the wind is much aft. In cither case, when the ship is iiot right before the wind, the remedy is the same : which is, totlirow the log or the line over from before the lee gangway, andto give a few fathoms more of stray line ; for which, however, intl^ie new method proposed, it would be necessary to apply a cor-rection, the quantity of which may be accurately ascertained. 3d. The motion of a ship in pitchi
. Archives of useful knowledge. liable to some additionalpull from being exposed to the wind. To this inconvenience, thelog line in the common way of heaving the log is hkewise expos*ed when the wind is much aft. In cither case, when the ship is iiot right before the wind, the remedy is the same : which is, totlirow the log or the line over from before the lee gangway, andto give a few fathoms more of stray line ; for which, however, intl^ie new method proposed, it would be necessary to apply a cor-rection, the quantity of which may be accurately ascertained. 3d. The motion of a ship in pitching. But this is not to beregarded as an objection ; for the rate of sailing is to be estimat-ed only, by what the experiment shows when the ship is going,steadily; in the same manner as in taking bearings, if the com-pass swings, we wait till it is quiet. Whenever the ship goessteadily for ten seconds together, or even five seconds, the pull<sf the line will be regulated to the average rate of sailing. GARNETTS PATENT SUITES. A B C D represents a ships block or pvilly, of which E is theaxis, having equal solid rollers, 111111, &c. nearly touching eachother; and situated between the axis, and the inside cavity ofthe block or pully. The rollers are furnished with axles in-serted into a brazen circular ring at each end, and are kept sepa-rate and parallel, by means of wires fastened to the rings betweeuthe rollers, and rivetted to. them. The ends of the axis E, arcfixed in a block after the usual manner. By this method indeed,some friction unavoidably takes place betwixt the axles of therollers and their sockets, in the brass rings, but as the quantity i2 IPAPEHS ON COMMERCE. of friction depends principally on the force by which the rubbingsurfaces are pressed upon each other, and as in this case there isbut the slight pressure occasioned by those accidental circumr-stances which would bring the rollers together, the friction mustbe too trifling to be noticed.* ^ The holes too
Size: 1584px × 1576px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bo, bookcentury1800, bookdecade1810, bookidarchivesofuseful03meas
