To make this parachute, we cut a circle ten feet in diameter out of a piece of calico, and divide its circumference into ten or twelve equal parts. At each point of division we attach a piece of fine hempen cord about three feet in length, and connect these cords with each other, as well as with the suspension chain, by ligatures that are protected against the fire by means of balls of sized paper.
In rockets designed to receive these parachutes, a small cavity is reserved at the extremity of the cartridge for the reception of 225 grains of powder. To fill the pot, the chain, d, is rolled spirally around the box, c, and the latter is covered with the parachute, e, which has been folded in plaits, and then folded lengthwise alternately in one direction and the other.
The parachute port-fire consists of a cardboard tube of from quarter to half an inch in diameter, and from four to five inches in length, closed at one extremity and filled with star paste. This is connected by a brass wire with a cotton parachute eight inches in diameter. A rocket pot is capable of holding twenty of these port-fires.
Parachute fires and port-fires are used to advantage in the operation of signaling.—La Nature.
Continued from SUPPLEMENT, No. 583, page 9303.
For preparation see page 9304 of SUPPLEMENT.