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stood for instance, a roof projecting 2 ft., and a porch projecting 2 ft. would throw the same breadth of shadow, which would also be 2 ft.; consequently, all shadows thrown on a surface at right angles to the objects throwing them are equal in breadth to the projection; but shadows thrown on oblique surfaces terminate where the angle of 45° from the projection would meet the oblique surface, such as the shadow on a roof from a chimney shaft, &c. Shadows thrown on surfaces parallel to the projection also terminate where the angle of 45° would meet the surface; and all shadows become gradually lighter towards their outer edge. Surfaces may be in shade when no shadow is thrown on them; for instance, one cant of the elevation of an octagon would be in shade, while the same part might throw a shadow. All shadows and shades are darkest at the side nearest the light; and they are generally made with Indian ink. These remarks as to the projection of shadows only apply to geometrical drawings.

Application of Colours. Finished plans are generally tinted with carmine, back-lined, and neatly printed with a crow-quill and China ink, having a scale, but no figured dimensions: but working plans are tinted in the natural colours of the materials used; that is, stone walls are coloured with sepia, brick with carmine, lath and standard partitions, and all other wood-work, with different-toned wood colours. Bearing timbers, or carpenter's work, are tinted darker than the finishing or joiner's work; and sections of timber are tinted much darker than either. A working plan of alterations has all the old walls tinted dark brown or grey; and the new walls, and every part where doors, windows, or fireplaces are to be broken out, tinted red. Slight sketches of elevations are touched up with a neutral tint of carmine and blue, or with sepia; but finished elevations are tinted in the natural colours of the materials represented; while working elevations have only a slight tint of blue on the roofs and windows. In tinting geometrical elevations, surfaces that are farthest back are tinted darkest, and projections, &c., in front lightest; but in perspective it is the reverse, for objects are lighter as they recede from the eye, and darkest in the

foreground, unless it is a surface on which the light shines. Thus, in shading geometrical figures, the cube, which would have three sides presented to the eye, would be light on the upper surface, a slight dark tint would be laid on one of the other surfaces, and the third would be much darker. So of a prism, or pyramid, and so also of a hexangular prism; for it is manifest that every shadow is a privation or diminution of light by the interposition of an opaque body. By attentively watching the shadows of objects when a brilliant sunshine presents them to our view, the truth of these remarks most forcibly strikes our attention. The same observation applies to shadows produced by artificial light.

South-east is the best aspect for an English house, and south or east the next best. Every cottage should be supplied with abundance of good water, and the drainage around it should be as complete as possible; few things contribute more to the comfort and health of a family than cleanliness within and about the dwelling which it may occupy.

tion is easier for the learner to practise than perspective*, we will describe it first; but before doing so, it may be well just to state the nature of perspective. It is, the art of delineating on a plane surface the representation of objects, so as to give them the appearance to the eye that they have in nature; consequently, the rays of light from the objects radiate to the eye, and the objects themselves diminish in proportion to their distance from the eye, in the representation as well as the reality. On the other hand, isometrical projection is the method of drawing the representation of objects on a plane by parallel rays perpendicular to it; consequently, objects do not diminish as in perspective. Indeed, if the observation be allowed, it is nothing more than a geometrical elevation upon an angle which foreshortens the parts of an object; but this angle must be defined, in order that horizontal and vertical lines may be measured by the same scale; therefore the given law is, that the isometrical representation of a cube should be made by rays parallel to its diagonal, which makes the three faces seen of equal form and size, and the boundary line a hexagon. A cube may be correctly projected in any other position; but we lose the advantage of being able to measure every part accurately if it is not projected by rays parallel to the diagonal and perpendicular to the plane.

Let abcd, in fig. 102., be the plan of a cube. Draw up

* Isometrical Perspective. This method of drawing was invented by Professor Farish of Cambridge.

the lines a l, bk, and ci; then, from the point f, with the triangle of 30°, draw ƒh and ƒg till they meet the upright lines. Make a de, an angle of 15°; then de is the height of the

cube, which set up upon fk, and draw ki parallel to fh, kl parallel to fg, Im parallel to k i, and im parallel to k l. The cube is now projected, and the three radii and six sides of the hexagon are all of the same length. All the oblique lines are drawn by the triangle of 30° first used one way and then turned over. The scale for measuring this cube would bear the same proportion to the scale of the plan that de does to da, and, if the side of the square were 4 ft., a d would be divided into four parts, and de would be divided into four proportional parts. In order to understand more fully the

plane of projection, and the rays perpendicular to it, let p q r s in fig. 103., be the diagonal plane of a cube: then tr is the diagonal line of the cube, and u v the plane of projection, while qu and sv are rays; then ur and rv are equal to any of the lines of the projected cube in fig. 102. - Circles are projected by drawing a square round them, and drawing the two diagonals of the square; then the four points where the circle touches the sides of the square, and the four points where it cuts the diagonals, give eight points, which, when projected, will enable the isometrical circle to be completed by hand.

It is obvious that the hexagonal figure 102. is symmetrical

with the cell of the bee; in which the radius is carried six times round the circumference of the circle: and the combination of these figures suggests a geometrical combination for tracing on the ground an elegant plan for a flower plot. For we hold it indispensable, that the young gardener should turn every portion of his knowledge to some account in his daily avocations.

Isometrical drawing is preferable to isometrical projection; the difference between them being, that the latter is projected in the manner just shown, but the former is simply drawing by the same scale used for the plan. The two projected cubes in fig. 102. show the proportion which isometrical projection bears to isometrical drawing; the inner cube is the projection, the outer one the drawing, and no in the latter is equal in length to be in the plan. In isometrical drawing we need not stop to consider the plane of projection or the rays, but proceed to work at once with the double tri

angle of 30°, fig. 104., which draws the oblique lines right and left. Take every dimension from the plan and elevations. Let fig. 105. be the block or outline

P

Fig. 104.