for the heart, lead a single wire from its bobbin up through the vertical shaft. This will form a sevenwire heart for the strands. Next fill the bobbins of a twelve-flyer machine with the same size wire. Pass all the wires up through holes, pass the top, arrange the wires through the grooves of the top, twist them together by hand, splice in a piece of rope and pass it five or six times around the drawoff drum. Friction straps attached to the bobbins g preserve an equal tension on the wires. Putting, now, the machine in motion, the seven-wire heart is drawn up the shaft, and at the same time the twelve single wires are wrapped about it as the disc revolves, each separate bobbin turning on its own centre in the opposite direction, so as to avoid twisting the wire. As the strand is formed it is reeled upon a bobbin. Having filled seven bobbins, six are placed in a laying-up machine, Fig. E, and one in rear for a heart. The heart, on motion being given to the machinery, is drawn through and the six strands wrapped about it, giving six outer and one central strand of nineteen wires each.

A, heart; B, draw off drum; C, friction drum; D, driving pulley; F, bobbins; T, top; V, tube; S driving shaft; R, reel.

Table of comparative dimensions of chain-cables, hemp rope, iron and steel rope, their weight per fathom, and breaking-strain.

Remarks.

No data for the weight of steel ropes smaller than 14 inch.

In practice it is advisable to take it at of the average breaking strain.

Proof strains to be as nearly as possible one-half the breaking strain.

Steel and iron wire rope, in accordance with this table, have a hemp heart.

The sizes of the wire given are those in use at the government rope-walk at the navy-yard, Boston, Mass.

NOTE. Column 1 is not a standard of strength of cables. Column 2 is intended to give, as nearly as possible, the size of chains approximating in strength to certain given sizes of wire and hemp rope.

APPENDIX B.

RULES FOR CUTTING AND FITTING HEMP BLOCK STRAPS.

Single Block, with Lashing Eyes. For the length to cut the strap, take twice the round of the block and once the round of the rope, and marry the strap once and a half the round of block, and half the round of the

rope.

Single Block with Thimble, or Hook and Thimble. Take twice the round of the block, and once the round of the rope. The rounds of the block, thimble and rope, taken once, is the length to marry the strap.

Single Block with Long Strap and Lashing Eyes. Take twice the round of the block, twice the round of the rope, and once the round of the yard. After splicing the two eyes, the length of the strap should be once the round of the block and once the round of the yard; and, after the block is seized in, the length of each leg should be one half the round of the yard. The seizing at the block will take up enough to give sufficient drift between the eyes for lashing.

Single Blocks with Straps to Fid out. Take once the round of the yard, once and a half the round of the block, and once and a half the round of the rope; at the distance of once round the yard, block and rope, marry the strap.

A Single Block with Double Scores, for a double strap. Take twice and a half the round of the block, twice the round of the yard, and once and a half the round of the rope. At twice the round of the yard and block, aud once the round of the rope, marry the strap. That which is taken up by the strap passing around the yard, will give sufficient drift between the eyes for lashing.

Double Blocks with Thimbles, or Hook and Thimble, as luff tackles, &c. Cut the strap twice the round of the block, and marry it once the round of the block, once the thimble, and two thirds the round of the rope. Grommet Straps. One length of rope makes three straps. double 10-inch block, 34-inch rope.

For a

fm. ft.

in.

1

0

3

8-inch thimble..

0

And this length is to be marked with chalk on the rope before unlaying.

If the grommet is made from four-stranded rope, it will only require three rounds of block, three of thimble, and enough to splice and to marry the strand, once round of block and once of thimble.

To Measure for Seizings of Block Straps. Supposing there are to be seven lower, six riding, and three cross turns-measure where the centre turn comes, which take as the average length of one turn, and allow as much for the six riders as the seven lower turns; this will give fourteen turns; then allow for the three crossing turns and splicing the eye, and there will be sufficient end left to heave the last crossing turn on, making seventeen turns in all.

If there are six lower turns, five riders and three cross turns, allow fifteen turns in all, and so on.

If the block is double strapped, allow five turns for crossing each way. To put a Seizing on the Strap of a Block. It should be well stretched, a few turns taken out and well rubbed down. Splice an eye in one end, sticking the ends once through, but not cut them off. Pass the eye round the strap, reeve the end through it and round the strap, as many times as required for the lower turns; then pass the end underneath the turns and through its own eye, leaving sufficient bight to heave the turns on; place it square round the strap, lay two strands of the splice down the strap, for the seizing to lay over it, heave the lower turns taut on, haul the slack through the eye, and heave it taut; lay the third strand of the splice on top of the lower turns, and pass the riding turns over it, put the end between the two last parts of the lower turns, and put the cross turns on; pass one round turn, which will be the centre one, and heave it well taut; then form a half-hitch on each side of the centre turn which will form a clove hitch with three parts, unlay the ends, make a wall or crown knot, trim off the ends and it is finished.

A double strap should be crossed both ways; first pass two turns between the strap that faces the side of the block, then bring the end out in the same direction as the sheave, and pass three turns there as before.

Proportions of Blocks to Straps, and to Size of Rope Reeving. For a common thick block, take one third its length for the rope reeving, as a 12-inch common thick block will reeve a 4-inch rope.

For a clump block, take one half its length.

For a thin block, take one fifth its length. For instance, a 12-inch block should reeve a 24 inch rope.

For a fiddle block, take one sixth the length of block.

APPENDIX Ù.

TO TURN IN AN OLD FASHIONED DEADEYE.

In turning in an old fashioned dead-eye in a hemp shroud, the principal caution is to keep the lay in the rope, as it prevents the wet getting in. If the shroud is to be wormed and served in the wake of the dead-eye, the worming should not be hove in too taut, as breaking the shroud round the dead-eye would probably snap it.

The score being well tarred, the end of the shroud is taken underneath, round the dead-eye, inside standing, or mast-head part; a bolt is put in a hole of the dead-eye. Take a good strand, knot both ends together; it is then middled and crossed round the end of the shroud; both bights are taken round the bolt, one on each side of the dead-eye, and a smaller bolt put in each of the bights, which are hove round the large bolt in the dead-eye. As the turns accumulate, it heaves the shroud taut round. The dead-eye should be secured through one of the holes, with spun-yarn, to the shroud before heaving, where the shroud is marked, for

Fig.A

Fig.B

the lower part. When the dead-eye is turned in, in a loft, the shroud is hove in with a jigger (or dead-eye machine).

When the shroud is hove well round, pass a good throat-seizing. When secured, take out the bolts, get a smaller jigger, hook one end to a strap round the end of the shroud, and the other to the mast-head

part; take a good strand, knot both ends together, take it round the end and standing or mast-head part; put a bolt in both bights, and heave it round, pulling up the jigger at the same time; this will bring the end taut up, as heaving on the strap brings both parts close together; then pass a round or quarter seizing, and a smaller one on the end.

In the figures A and B, the quarter seizing is omitted to show the direction taken by the shroud.

To Turn in Cutter Stay Fashion. Put a temporary seizing on the cross; carry the end round the standing part, and heave it taut alongside its own part; then seize those two end parts together with a throat seizing, making the eye as small as possible, put a quarter seizing (a flat one) on as well, about