Scientific American Supplement, No. 829, November 21, 1891 eBook

This eBook from the Gutenberg Project consists of approximately 124 pages of information about Scientific American Supplement, No. 829, November 21, 1891.

Scientific American Supplement, No. 829, November 21, 1891 eBook

This eBook from the Gutenberg Project consists of approximately 124 pages of information about Scientific American Supplement, No. 829, November 21, 1891.
J fixed to the outside of the tube, and as the descent of the piston into the mercury is directly proportional to the weight of the body attached to the hook B, the divisions of the scale will all be equal.  It will thus be seen that the apparatus is extremely simple in theory, and it only remains to construct it in such a form that the mercury may not easily be spilt in moving the instrument from place to place.  This is effected by causing the cross head E to fill the tube while working freely therein, and a small valve is arranged to allow for the passage of air.  The cross bar G can be regulated upon the rods by means of set screws.—­Industries.

* * * * *

REEFING SAILS FROM THE DECK.

While this method may be applied to topsails and top-gallant-sails, I especially apply it to courses, which, being so difficult to reef the old way, may by this method be reefed from the deck in a few minutes.

After several years of trial by myself and others, on voyages around Cape Horn under all circumstances of weather, of sleet and snow, this method has always given the utmost satisfaction.

[Illustration:  REEFING SAILS FROM THE DECK.  Front View.  Rear View.]

The average time required for reefing and setting was noted for five years, being seven and one-half minutes.

This trial was made on a mainsail, the yard being seventy-one feet long, and reefyard sixty-six feet long, eleven inches diameter at center and nine at yard-arms.

By reference to the drawing it will be seen that it is not necessary to have clewgarnets or buntlines in reefing.  The operation is performed by easing of the sheet and hauling the lee reef-tackle first, also the midship reef tackle.

When the yardarm of the reefspar is up at the lee side, the sail cannot sag to leeward when the tack is eased away.  Now haul the weather reef-tackle likewise midship, snug up to the yard, belay all down the tack, and sheet aft.

As all the reef-tackles lead to the slings of the yard, there is no impediment in swinging the yard when the reef-tackles are taut and belayed.

The slack sail will not chafe, as it remains quiet, but if so desired may be stopped up at leisure with only a few hands with stops provided for that purpose.

In case of a sudden squall the sail may be hauled up the usual way.  The buntlines will draw the part of the sail below the reef well up on the part above the reefyard, and remain becalmed, while the weight of the reefspar will prevent any slatting or danger of losing the sail any more than any other sail clewed up.

In case there is steam power at hand, all three reef-tackles may be hauled simultaneously, easing sheet and tack sufficiently to let the wind out of the sail without shaking.

There are other advantages gained by this method; while its essentials are positive, quick reefing from the deck in all weathers, it is also better reefed than by the old method.  For by this new method the sail is not strained or torn, and the sail will wear longer, not being subject to such straining.

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Scientific American Supplement, No. 829, November 21, 1891 from Project Gutenberg. Public domain.