The shadow of the point f evidently falls on the edge of the prism at fs, see plan. This point f is one end of the shade line fg, therefore f is one point in the shadow of fg on the front face of the prism B. The line fg being parallel to this front face, its shadow will be parallel to the line, therefore from the point fs we draw the horizontal line f,s.r1s

If from the point r1s we draw the projection of a ray of light back to the shade line fvgv we determine the amount of the line casting a shadow on the front face of B, that is to say, the distance fvrv. The shadow of the remainder, rvgv, falls beyond the prism on the V plane, and is evidently the line rvsgvs. Thus the shadow of the shade line from e to g has been determined.

The next portion of the shade line, gc is a vertical line and we have already obtained the shadow of the end g. Since it is a vertical line its shadow on V will be vertical and equal in length. Therefore draw gvscvs.

There remains now only the edge, cdt of which to cast the shadow. The end d being in the V plane must be its own shadow on that plane. (§ 39) We have already found the shadow of the other end c, at cvs. Therefore dvcvs is the shadow of dc and completes the outline of the shadow of the plinth.

It will be noted that dvavs is a 45° line, which would be expected since the edge do is perpendicular to V.

49. Considering next the prism B, we find by applying the projections of the rays of light to the plan, that the front and left-hand faces are in light, and that the right-hand face is in shade. Therefore the only shade line in this case is the edge mn. The upper part of this, myr1s is in the shade of the plinth and therefore cannot cast any shadow.

It is to be noted that the ray of light from the point rv in the plinth A passes through the point r1s in the shade line of the prism B. In finding the shadow of this point at rvs we therefore have found the shadow also of one end of the shade line nr. Since nr is vertical, its shadow will be vertical on Y. Therefore draw rvswvs. This line completes the shadow of the two objects upon the V plane.

RESIDENCE OF MRS. BACHRACH, WASHINGTON, D. C.

Wood, Donn & Deming, Architects, Washington, D. C. Walls of Stucco on Wire Lath. A Three-Quarter Engaged Ionic Column Used on Entrance Feature. For Plans, See Opposite Page.

SECOND FLOOR PLAN PLANS OF RESIDENCE OF MRS. BACHRACH, WASHINGTON, D. C.

Wood, Donn & Deining, Architects, Washington, D. C.

From the point of shadow wvs draw the V projection of the ray back to the line nvr1s. This shows how much of the total line nr falls upon V, and how much upon II.

The shadow on II of the portion nw will be a 45° line since nw is perpendicular to II. The point n being in the H plane is its own shadow on that plane.

It is to be noted that the point whs is on the perpendicular directly below wvs.