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between these one or two short sticks should be placed, so as to mark accurately the straight line joining them.

In selecting these stations we should endeavour to avoid obstacles between them, such as houses, thick woods, &c., so that we could measure between the two points.

Having provided ourselves with a measuring-chain, which is 66 ft. long and divided into 100 parts called links, an arrangement well suited for obtaining acreage: a measuring-tape, or even a common rope divided into yards, will do; also take a staff about 10 ft. long, or 10 links long if using a chain; a note-book with two ink lines down the middle of a dozen or so pages, and we are provided with all the necessary articles for our survey.

We will suppose that we are using a chain, with which ten pins or arrows are used, an arrow being placed in the ground by the chain-leader at the end of each chain, which arrow is taken up by the chain-director as the latter comes up to it; thus the chain-director knows how far he has gone by the number of arrows in his hand.

Starting from the station, O, we write at the bottom of the page in our notebook, which is termed the “field-book,” the name of our station and the line

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along which we are working, thus, "Line O P from o." Before beginning to measure along O P, we should with our staff measure the distance of the hedge from the point o, and insert this on the proper side of our double column in the field-book. Suppose this distance to s to be 20 links.

Next measure along O P, noting where hedges cross the line, and where the hedge on the right bends. At each bend measure to the hedge, this measure being termed an "offset," noting at what distances up the line OP these offsets are taken.

Suppose that at 110 links we measured to the bend T 40 links, at 200 links to the bend U 90 links; at 280 suppose the hedge crossed our line, and we

measured to v an offset of 20 links. In a similar manner offsets would be measured to w, x, and y, till we come to P, where the total length of our line we will suppose to be 940 links.

Referring to the representation of our field-book, we can see how this result would be booked.

We have from this one line and the offsets sufficient information to enable us to sketch the hedge from 0 to P, as well as a portion of the cross hedges. In like manner we should measure from P to Q, Q to R, and R to O, and by means of offsets we obtain the house, hedges, &c., near these lines.

Next measure “check-lines,” as they are termed, from P to R and from R to P, noting as before offsets, crossings, &c.

Before we commence details we should test whether our work so far has been done correctly, and this we can discover as follows ·

On a piece of drawing-paper, sufficiently large for the scale we have selected, draw the line o Q or P R. Then, taking a distance equal to O P in our compasses, describe an arc with O as a centre, so as to pass near where we suppose P to be; then, with Q as centre and the distance Q P, describe another arc : where this second arc intersects with the first will be the point P. In the same manner fix the point R; then, if the work be correctly done, the distance P R will be the same on the plan as it was found by measurement.

The diagram, Fig. 3, would be the appearance of our plan at this portion of our proceedings, and we should now have to fill up details. These details are all done in the same manner, so we will give but one example, viz., the method of getting the banks of the pond, F, Fig. 1, correctly.

On looking at Fig. 2, we find in the line o Q the letter H; this letter represents the position of a stake in the ground, or a mark cut there, or some station that we noted as we measured along the line o Q, this mark being registered in the field-book, and called "bench-mark" (B.-M.), in the following manner: "B.-M. 320, in line o to Q." In like manner the bench-mark K would be noted. We could, therefore, plot the line H K, because we know its termination in the two lines o Q and O R, and we should measure its length and take offsets to the pond wherever there was a bend. By proceeding in the same manner with the small line L M, we should by means of offsets get the side that alone remained to be surveyed.

In this manner hedges, &c., could be sketched, and thus the whole of the enclosures could be put correctly on the map.

In order to make a sketch complete, we should tint the streams and ponds light blue, the houses red, and the roads a light burnt sienna colour

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When a plan has been made we should know how to obtain what is called the area of the fields; that is, how many acres, roods, and perches it contains. To do this is very easy, if we have made our survey with a 66-ft. chain, because 100,000 square links are equal to an acre.

Suppose C A DEF B to be a field, the area of which is required. We cut this field up into triangles, such as A B C, A B D, DE C, C F E. Then by dropping perpendiculars, such as C x, we measure A B, and multiply this by half C (these measures being taken off our plan), and the product will be in square links. Suppose we thus obtain 325,674 square links, by striking off five figures to the right we obtain 3 acres, and the 25,674 will be decimals of acres, which we can mul

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tiply by 4 to obtain roods, and 40 to obtain perches, thus obtaining our acreage in acres, roods, and perches.

When a hedge bends or twists, we must draw one side of our triangle so as to make a balance between what we throw out of the field and what we take in, care being taken that we use so many triangles as to leave this estimate but for a very small amount.

A very correct survey of a portion of ground of two or three miles square may be made by this means.

HEIGHTS AND DISTANCES.

Under the head of surveying we may fairly class obtaining the heights and distances of inaccessible objects. To be able to measure the height of a tree or of a building, or to get the distance across a river, is a very useful proceeding, and as this is a very simple problem, we will describe the method.

When the sun shines the tree will, of course, throw a shadow. We can then either pace the length of the shadow, or measure it with our walkingstick, the length of which, in feet and inches, we should always know. We may then place the walking-stick upright in the ground, and should prove (by means of a plummet-line, which may be easily made with a string and a stone at the end) that the stick is upright: then measure the length of the shadow cast by the stick.

Suppose we found the shadow cast by the tree to be 40 paces, and we know our usual pace to be 30 in., then the length of the shadow would be 1,200 in. Suppose, also, the length of the shadow of the stick was 50 in., and the stick was 36 in. long Then by simple proportion we say, "as the length of the shadow cast by the stick is to the height of the stick, so is the length of the shadow cast by the tree to the height of the tree." Putting this in figures it becomes as 50: 36: 1,200 to the height of the tree. By multiplying, as in rule of three, the second and third together, and dividing by the first, we obtain 864 in. for the height of the tree, that is, 72 ft.

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In case the sun does not shine, or we cannot conveniently make use of the shadow, another simple method is to place a stick in the ground, then to lie down and place the eye close to the ground, and so that the top of the tree coincides with the top of the stick.

Thus E represents the eye, S K the stick, and T R the tree; and K, the top of the stick, and R, the top of the tree, are in line when seen from E.

Then measure E S, and E T, also S K, the height of the stick. Suppose Es

2 yds., S R, I yd., and E T, 50 yds. Then, as ES: SR: ET to the height, TR; that is, as 2: 1 :: 50 to 25 yds., or height of tree.

Another method for obtaining the height of an inaccessible object is to get a piece of paper, and by doubling this, cut it into an exact square. Then when the square is made and doubled it will be in this (Fig. 6) form, and the two lesser sides should be equal in length. Double in a small portion of the paper at one end, so that it looks thus (Fig. 7). Then by holding this in the hand, and looking at our own height on the stem of the tree along the line C A, with the eye at C, walk backwards or forwards till the line C B points to the top of the object whose height we require. Then measure from the point on which we are standing to the tree, and the height of the tree will be equal to this distance added to our own height.

The reason of this is that the angle B C A is 45°; therefore the side C B is equal to the side A B.

'We can practise this method in a room, or with regard to a house, and can thus impress it on our memory. it is a good plan to have a piece of cardboard cut in the manner shown above, and carried in a pocket-book, to be used when

necessary.

It often surprises the uninitiated to find how much we can do by the aid of a piece of rope in regard to distances. To accomplish anything we must first know how to set off a right angle on the ground, and this we recommend to be practised with a piece of thread and two or three pins on the floor of a room.

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First take a piece of thread (or rope) and at the ends make two loops; then suppose it is required to set off a right angle from the line joining D and A and in the direction of E. Make a mark at C in the line A D less than half the length of the rope, also a mark at B equal to A C and in the same line with D, C, and A. Make a mark in the middle of the rope, which middle can be found by doubling the rope in half; then place the loops at the end of the rope over two pickets to be driven in the ground at C and B, and draw out the centre of the rope towards E and until the sides C F and B F are equal, when the line joining A and F is at right angles to the line joining D and A.

By adopting this method we can always set off a right angle from any selected station, and the use we may make of this will now be shown.

Suppose we are on the bank of a river, and wish to know the distance across,

or that we see any far-off object, the distance of which is required. By means of two right angles set off carefully on the ground we may obtain the distance in the following manner:

Suppose x Y the distance required across a river, we being on the side y. From Y set off, as before mentioned, the right angle X Y A, and let y A be nearly equal to x Y (to be obtained by guess). From A set off A B at right angles to Y A, and at any convenient point down the line A B make a mark at B, where a point, C, in the line A Y is also in line with B and A. Then measure A B, A C, and C Y; by proportion we then have: as CA: A B C Y : X Y. Suppose C A, 40 yds.; A B, 70 yds.; and C Y, 300 yds.; then, as before, as 40 yds. 70 yds.: 300 yds. 525 yds., the breadth of the river.

We may practise this method in a room on a small scale, or on a lawn, and thus impress the process on our mind, and have it ready for use whenever required.

Every person should practise pacing distances, so as to be able to pace correctly, and to know the proportion between his paces and the number of yards he has gone over. The average walking-pace is about 30 in., or five-sixths of a yard. If this pace is used, every 120 paces will make 100 yds., and so on in the same proportion.

There are three good methods of pacing distances: the first is to pace regularly on, and at every 100 yds. to pass a stone or piece of money from one hand to the other, so as to remember the 100 yards; the second is to count only when the left foot comes to the ground, then double the number of paces; the third is to use a walking-stick in the usual way, and every time the point comes to the ground to count one; then multiply the result by four, and we obtain the number of paces.

In connection with pacing, judging distances may be referred to. Every soldier is now instructed in judging distances, and every volunteer ought to know something of this subject. The best method is to practise at some known distance, and judge how much of the details of a man's face we can see at say 50 yards, also at 100, and so on. Another plan we have found very good in practice is to select a point about 22 yds. in front of us, this 22 yds. being selected because it is the proper distance between the wickets, and can, therefore, be easily estimated by all who are cricketers, as all ought to be. Then take another 22 yds., and so on. We get 12 yds. under 100 yds. by taking four such measures, and we can then take a half, and reach close to 100 yds. By this plan we can after a short practice estimate very nearly 100 yds., after which we may estimate a second 100 yards, and so on.

Sometimes we may make the dullest walk interesting by guessing at distance along a road and then counting our paces towards them. We can easily train ourselves so as to estimate within about five per cent

We can ascertain long distances with very fair accuracy by means of the velocity of sound, so that when a gun is fired and we see the flash, we can ascertain how many seconds elapse between our seeing the flash and hearing the report. Sound travels at the rate of about 370 yds. per second; so that, if provided with a watch that has a seconds hand, we can count the seconds and multiply the number that pass between the flash and report by 370, and we obtain the distance in yards.

We can by this means tell how far a flash of lightning has occurred from our position.

In case we have not a watch, we may count the beats of our pulse; these

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