T

HE showing of steam pipes on floor plans is a matter that calls for attention, and in this connection we give Figs. 148 and 149. The method shown in Fig. 148 is the one which is probably most used, the pipes being represented by single lines, and the risers by circles.

The other method shown in Fig. 149 has the advantage of showing the connections of branches with the main, more in detail than the method just mentioned. A glance at the sketch will show that the tee on the main is turned at 45 degrees,

and a 45-degree ell brings the branch level again.

Now we come to the matter of showing piping in perspective, the last point which we shall take up in this series. It is of much importance, for it will be found that it is used a great deal, and furthermore, many systems of heating are very difficult to illustrate by any other means.

To get into this subject we show several simple examples of perspective in Fig. 150.

A represents a connection which inspection will show is viewed by looking down upon the object, and from the right,

while B is obtained by looking downward from the left. Either of these two views is very common, much more so, we may say, than views obtained by looking upward upon the object. C shows a connection which is viewed from the left and on a level with it, instead of downward or upward, and occasionally is a desirable method to follow. D shows a little more difficult perspective than those preceding, and E shows valves in two different positions, in perspective.

A close study of these examples of perspective will show that the ellipses which are seen on the fittings are square with the direction of the pipe, no matter in what direction the pipe may run.

Compare F and G, which are supposed to represent the same thing. The ellipses in F are not square with the fitting or pipe, while those in G are. The result is apparent. The tee in F is distorted, while that in G is not.

If our reader will hold a piece of pipe in front of him with the end pointing toward him, that end will appear as a full circle, but if he will turn the pipe from this position gradually until it stands lengthwise instead of endwise, this circle will become an ellipse, gradually narrowing, until finally, when in a position lengthwise, no part of a circle or ellipse is to be seen, simply the square end being seen.

Perhaps this crude example will explain why, in this perspective work, the circles on the fittings appear as ellipses. In making a rule for this work we can perhaps do no better than to say that the straight lines of pipe should be first put in, in their proper directions, and the fittings connecting them put in afterward, and as previously stated, care be

ing taken that the ellipses are square with the piping.

To make an application of the work shown in Fig. 150, we give Fig. 151, which represents a heater with its piping. It

Fig. 149.

will at once be seen that the perspective of this work shows that it is obtained by viewing it looking downward and toward the left. The boiler was drawn first, with the lines V and W at 60 degrees with the horizontal front line of

the boiler. In perspective, all vertical lines appear vertical, hence all the risers in Fig. 151 are vertical.

The line of pipe S-T is at right angles to the boiler and therefore must be parallel with the front line of the boiler, that is, horizontal. The lines A-B and K-L are of course parallel with the lines V and W of the boiler, and must therefore be drawn in that way, that is, at 60 degrees with the horizontal.

The lines of pipe shown at C, D, M and N are parallel with S-T and E-F, and are therefore drawn horizontally with the tee square.

The lines of pipe shown by G, H, P and R being on the, work itself parallel to A-B and K-L are drawn parallel, that is, at 60 degrees with the horizontal.

In Fig. 151 we have lines of pipe running in four different directions in addition to the vertical lines, and we believe that this sketch will cover the ground

quite thoroughly, and therefore be of special value.

We might say that in perspective, the lines that run back, and away from the observer, appear to converge instead of appearing parallel, as they actually are.

This is illustrated by a straight line of railway tracks. We all know that if we look along a long stretch of track, the rails appear to converge, and if the distance is great enough, they seem finally to run together.

To be actually correct in showing the work of Fig. 151, the lines of pipe A-B and K-L, instead of being parallel; should be somewhat closer together from B to K than from A to L, but in mechanical perspective, as we may call the work that we are now considering, this principle is

not usually given any consideration.

Very often on such work as shown in Fig. 151 the work as far as we have carried it, is shown in perspective, while the radiators, and all other work above the connections in the cellar, the work would show plain, just as we have hitherto shown it.

In bringing this book to a close with the present chapter we would say that we have endeavored to eliminate as far as possible all technical matters connected with the subject, trying as far as possible to express and explain the ideas to be conveyed in as straightforward and plain wording as possible, for it has been our aim to make the book equally as valuable to the apprentice boy as to the well informed master.

House Drainage and Sanitary Plumbing,

by W. P. Gerhard.

Hydraulic Tables, by P. J. Flynn.

Recent Practice in Sanitary Drainage of Bldgs. Wm. Paul Gerhard,

Sanitary Condition of Dwelling Houses, by George E. Waring.

Sewer Gases, Nature and Origin, by De Varona.

Sewerage and Sewage Purification, by M. N. Baker, Ph.B.

The Treatment of Sewage, by Dr. C. M. Tidy.

The Disposal of Household Waste, by W. Paul Gerhard.

Water and Water Supply, by W. H. Corfield.

These books are for sale by The Plumbers' Trade Journal, P. O. Box 715, New York City, and will be sent to any address on receipt of our list price. No books sent C. O. D. While these books are thoroughly good and instructive reading, still we want it understood that we do not recommend any special one.