This section is from the book "The Gardener V2", by William Thomson. Also available from Amazon: The New Organic Grower: A Master's Manual of Tools and Techniques for the Home and Market Gardener.
In Lesson No. XIII. (January 1878, p. 34), a few hints were given about how to find the centres required to draw the various outlines of walks, etc, on plan fig. 37, by means of the compass. In laying out such a plan as is referred to, some of the curves will be found of too wide a radius to be worked from their respective centres. The carriage-road, for instance, could not be very conveniently taken from the centres as it has been drawn on the plan. The perpendicular lines necessary in drawing a working plan may be retained and utilised by drawing lines at right angles to them to certain points, and measuring such distances as may be required to ascertain the position of such points on the ground. To make this easily understood, suppose that line a b, fig. 63, is one of the lines just mentioned, or that has been drawn (as it really has) for the purpose of measuring from, but drawn square with any other lines previously on the plan. We shall draw another line, c d, at right angles to a b, and make the intersection of the two a starting-point. This happens to be near the centre of the carriage-road, and from that point to where the line a b crosses the edge of the drive, is on the one hand 10 feet, and on the other 14 feet.
Mark this upon the plan on the line between the points measured from. Working up the line a b, the next line that crosses it is a shrubbery outline, and it will be found to be 38 feet from the edge of the drive, 12 feet from the former line. Another line, e f, will be desirable - at right angles, of course; and from this point a fresh start may be made to measure right and left, and further up the line, marking each measurement between the different points. Returning to where we started, and measuring to the left on line c d, 20 feet from the intersection of the two lines, another point will be found on the outside edge of the carriage-road: 33 feet from this point draw a short line at right angles to c d, which will intersect the edge of the drive 15 feet from c d. A similar line drawn at a distance of 40 feet, will intersect it at 23 feet; and so the proper curve of the road may be found without the aid of a centre. In the same way, the curve on the right hand of a b may be found by drawing lines from c d at various points to cross the road; and measure the distances in the same way as above. These lines must be marked on the ground by means of a rod at each end, and at least one intermediate one. This does not apply to the short side ones, only the main lines.
A square will be useful to guide the tape-line in placing pegs at the various points on the short lines, if a line is laid down on the main lines, from which measurements are being taken. At fig. 64 is represented a very simple but very useful instrument for such work as this. It is simply a piece of deal, a foot of 14 inches square, fixed on to the top of a stout rod about 4 feet long. On the top side of the board two lines should be drawn exactly at right angles, and at the extremity of each line a short brad inserted, so that they project from the board half an inch. They must be right upon the lines, and stand straight; the ends will be all the better if filed smooth and round. To show the usefulness of this home-made instrument, we will again refer to fig. 63. The line a b having a rod at each end and one at i, get a fourth rod and place it at g, on a line with the other three; lift this rod out, and place the instrument described above in its place, and turn it round till two of the brads are on a line with the rods on line a b.
Now, if measurements are wanted out to the right towards n, hand the rod taken out at g to an assistant, with the end of a tape - line, while you retain the reel, and hold it at whatever distance is required; and at the same time, direct the assistant to place the rod on a line with the two brads on the board, which will give you a line at right angles to line a b. Just a hint more to the assistant who is at the end of the line. Place the ring of the tape-line on the forefinger or thumb of the hand you intend holding the rod; take the rod between the fore-finger and thumb about 6 inches from the top, and allow the rod to hang down plumb, keeping the line tight and the rod just clear of the ground. He will thus be at liberty to move easily backward or forward, as he may be directed - moving, as it were, on the circumference of a circle, ready to drop the rod into the exact spot wanted. By this means right-angle lines can be set off without a line at all. This simple instrument is also very convenient when measuring a piece of ground preparatory to drawing a plan, as it is important to have the correct outline, and the positions of any trees or other objects, properly ascertained; and this can only be done by following a similar course to that just described and illustrated in fig. 63. If a plan of fig. 63 was required, and the measurements to be taken on the ground, similar lines to those shown would have to be sticked out and measured from, and the measurements marked upon a rough sketch in note-book, before the plan could be produced on paper.
I have been thus particular to show how a plan can be correctly laid down without the aid of the centres from which they may have been drawn on paper, because I think it sometimes of importance. But however important it may be in connection with geometrical flower-gardens to have everything exactly to fit, I do not wish it to be understood that I would be very particular as to a few feet or inches in laying out such a design as is given in fig. 37. If the ground was all of an even surface, of course there would be no need to deviate in the least from the plan; but if the ground has been made, or is naturally undulating, the outlines will in many cases vary considerably from your plan - the eyes here taking the place of the compass, to make the curves suit the ground. It will be easily understood that an undulating surface is of greater area than a plain surface of the same dimensions, and for that reason it would not be possible to follow exact geometrical rules; and if it were possible, it is not desirable, as any one with a good eye can make lines suitable to the ground with less trouble than by the rules of geometry. I believe landscape-gardeners generally have a great abhorrence to anything of geometrical stiffness coming in contact with their few and easy-flowing lines.
With this, to a certain extent, no one will differ; but I think some landscape-gardeners carry their ideas, in some instances, too far in the direction of a wild garden where there is no space for that purpose - and many gardeners err as far in the other direction in having too much of the ginger-bread style.
And now I must take leave of those of my friends who have followed me to the end. In my endeavours to go over and be understood on all points mentioned in our programme, I am afraid I may have repeated myself on some occasions, and that some of the papers may have had a "jumbled" appearance. But I hope these and other faults will not detract from their general usefulness, and that they may be the means of leading some to study that higher art - landscape-gardening. R. Inglis.
[We are happy to know that these Lessons in Drawing have been much appreciated by those for whom they were intended. Mr Inglis, we are glad to say, is busy rewritting and improving them for publication in book form. As this is the last lesson in drawing, we intend to publish in our March number the first instalment of 'The Gardener's Primer,' also intended for young gardeners. - Ed].