The step is commonly supposed to be 3ft., and the pace 5ft., but this is a most uncertain mode of measurement; a man may step 3ft., measuring from the heel of one foot to the toe of the other, but even if he does so two steps must be less than 6ft. by the length of his own foot, and very few men can take with any correctness a hundred consecutive steps or paces. Besides which so many travellers confound the terms step and pace that it is impossible to tell which they mean; it is much better, therefore, to use the word yards and to measure them by a military pace stick; this may be two light sticks like a walking-cane sawed down the middle and riveted at the head like a pair of compasses; then if, at 1ft. from the joint, a stick of 1ft. in length be fastened across the opened legs they will form an equilateral triangle, and the points will be 3ft. apart; with these, used like a pair of compasses, a man may measure off 100yds. almost as fast as he could walk it, and would be certain of his distance. A forked branch cut on the spot and trimmed, so that the ends are 3ft. apart, answers the same purpose.
HITCHES ON MEASURING LINE.
For measuring a base for rough triangulation, a fishing line of 100ft. is easily carried; three measurements will give 100yds., and six will give as many fathoms. 120 fathoms is a cable’s length, a common and useful unit in maritime surveying. To measure successive lengths let your line have a little stray end beyond the marks, and as the hanks are usually sold in lengths of 120ft., an overhand knot may be turned, 10ft. from each end, to mark the 100ft. Stick a perfectly smooth peg in the ground, without projecting head or catch of any kind, make a loop in the end of your line, and put it over the peg, carry out the 100ft. and put in another peg, then jerk the line upward, and you will cause a wave to run along it which will lift it off the end of the first peg (Fig. 1); but, as a permanent loop might catch thorns or projecting branches, it is well to make it with a hitch (Fig. 2), so that it may shake out as it comes off the peg, and leave only a free end to be hauled in. Several hitches, or a sheepshank (Fig. 3), might be used for this purpose, but probably none would answer better than the signal halyard hitch (Fig. 4), and with this the end may be made fast to any convenient tree or bush that stands fairly in the line you wish to measure. Pass the end twice round the branch or peg, then taking the end and a small bight of the measuring part, hitch them as if you were going to tie a reef knot, pull the first hitch tight, but do not complete the knot by making the second hitch; this will hold quite fast enough, and a slight jerk will be sufficient to set it free when you wish to haul in the end. Hitch it to another branch, and so in succession you may measure any number of lengths you wish, taking care always to keep the several pegs or points of fastening in a straight line.
A measuring line should merely be straight upon the ground, and never be subjected to any tension, still less should it be lifted up and then stretched to a straight line in the air; slopsellers know this when they ask sailors to hold up a length of serge while it is being measured, but any experienced hand meets this by insisting that his cloth be laid fairly on the deck and measured there.
To make or build wheels.
The first step in diminishing the labour of dragging a heavy body along the ground is to put rollers underneath it, and the use of these is exemplified in the earliest Assyrian monuments; but these are left behind as the mass moves onward, and have to be constantly carried forward and replaced beneath. The next step is to connect them with the mass, or with the carriage supporting it, by axles, forming either integral parts of the rollers and turning with them, or by fixed axles, on which the rollers or wheels revolve. It is probable that many of the ancient vehicles were supported on axles revolving with the wheels; but we now only retain this form in that of the wheelbarrow, and the simplest way of making this, where timber is cheap and plentiful, is to cut a log of sufficient length, then to saw or chop down the ends so as to leave a disc of sufficient size and thickness in the centre, with two arms projecting from it to form its axle, as shown in Figs. 2 and 3. The barrow itself may upon occasion be made of a forked tree, of which the single part is thick enough to have a space cut in it to receive the wheel, while the two branches serve as the handles, and minor ones from them perhaps answer the purpose of legs; otherwise a rough frame, as shown in our sketch, may be built, and pegged or treenailed together.
