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120 MECHANICAL AND ENGINEERING DRAWING 121 of its projection, although radically different to either its plan A, No. 1, or its elevation B, No. 3, is still nothing more than an ordinary pro- jection of the original object when in its changed position. This is further shown in No. 2 (Fig. 157), where a side view is given of the plate with the block upon it, such as would be seen when looked at in the direction of the arrow/, No. 1. Then by the aid of a few projectors from No. 2 and No. 1, it is seen that C, No. 3, and D, No. 4, are just ordinary projections, differing little from those which have preceded them, and certainly no more difficult to obtain than some which the student has already projected or drawn. As the projections of the object given in this figure form a problem for solution later on, we defer showing how they are exactly obtained until we have, as in previous instances, explained how the projections of simple " figures " in similar positions are found. 53. Now, to facilitate the process of finding the projections of an object when inclined to the VP and HP, we have to introduce into the construction an imaginary inclined plane interposed between the VP and HP, on which the object whose projections are required is assumed to rest. This plane is represented in Fig. 157 by the line OP, No. 2, and is the only new feature in our subject of study, it being not a fixed plane like the VP or HP, but one that may assume any desired angle with those planes. Such a view of an object as is shown in No. 2 (Fig. 157) could of course be given without the assistance of the line OP; but as it determines the inclination of the object to the vertical or horizontal, it is of material help in finding its projections,