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 up and submitted, as was the proposed bridge shown in Fig. 168, is more likely to receive favorable consideration than one in which only the ordinary blue prints and maps are used.

Engineering Record

Fig. 168. Sketch of a Proposed Concrete Bridge for Portland, Oregon, Drawn on an Actual Photograph to Show the General Effect if the Bridge Is Built

Points a measured distance apart on the site of the bridge are plainly marked so that they will appear in the photograph and show both the scale of the photographic reduction and the location of the bridge. The bridge is then drawn in on the photograph by hand work

If maps must be printed in a report, a book, or a magazine, it is usually necessary, on account of the high cost of color printing, to use some arrangement of black ink for shading those areas which on a single map would ordinarily be colored by hand. Fig. 169 is a sample of what can be done without the use of color. If the drawing is made considerably larger than the finished illustration, the shading can be put on effectively by hand work. Mechanical shading by the Ben Day process, as regularly used by good engravers, gives excellent results but its use makes zinc cuts rather expensive. Many illustrations in this book are made by the Ben Day process. Anyone wishing to know more about the possibilities of this process should look up Fig. 233 or consult the engraver who is to make the line cuts.

Often the matter to be presented calls for maps of a large size, which can be obtained only at considerable