As all the illustrations mentioned were made with the idea of reproducing them as lantern slides, which are only about three inches square, they do not indicate the full power of the attachment in a single case. Therefore I placed my camera near a window in one of my rooms and photographed the row of dwellings across the back yards [p. 465]. The actual distance from the camera to the first dwelling is one hundred and thirty feet; to the chimney, one hundred and fifty-four feet. Then, after putting on the telephoto attachment and extending the front of the camera as far as the bellows would permit, I telephotographed one of the chimneys on the third house, the only change in the camera being a slight inclination so that the chimney would be in the centre of the plate. This picture, when compared with that taken with the ordinary lens, shows an enlargement of nearly sixteen diameters, which is considerably more than the capacity or power of a very large field-glass. [Illustration: From My Window. (The house is 130 feet distant.)] [Illustration: Chimney of Third House, 154 feet from My Window.—Telephoto Lens, full power, sixteen diameters.] [Illustration: Popocatepetl, Thirty Miles from Hotel Jardin, Puebla, Mexico.] [Illustration: St. Mark's Cathedral, Venice.] Although some of the detail is lost in half-tone reproduction, yet the vast difference between the ordinary photograph and the telephotograph is well shown. The telegraph wires and the other details which are not visible in the former are clearly brought out in the latter. The exposure with the ordinary lens was about one-thirtieth of a second, while that with the attachment was one-fourth of a second. One-fourth of a second may seem to be a very short period of time, but it is entirely too long for many subjects that are very desirable. [Illustration: Popocatepetl from Same Point of View, Thirty Miles Distant—Telephoto Lens.] [Illustration: Left Mosaic of the Cathedral, Venice, from Piazza at a Distance of More than 200 Feet—Telephoto Lens.] The shortest exposure I have ever made with the attachment was upon a very fruitful specimen of the cocoanut-tree on the island of St. Kitts, one of the emerald gems of the Lesser Antilles, belonging to Great Britain. After making an instantaneous picture in the ordinary way, I used the attachment on the cocoanuts, making use of a drop-shutter giving an exposure of about one-tenth of a second. As the tree was swaying with the strong trade-wind a very quick exposure was necessary, and thanks to the intense light the plate responded to the application of a powerful developer [p. 464]. [Illustration: Telephoto of the Bronze Figure of Victory on Memorial Column at West Point. (Distance 100 Yards.)]