Excerpt from Impressions of AmericaTurn back now to (i), i.e. The experiment with the forefinger alone, and keeping the attention fixed on the finger, look first at some object not very far behind the finger (i.e. On the side of it away from the eye), and then at some object much further off: you will notice that the further off is the object at which you look, the greater is the distance between the two images of the finger, so that by looking at an object a suitable distance away, the two images of the forefinger may be made to move as far apart as we wish, within certain limits. It is in this way that we can bring the two stereoscopic pictures into coincidence, and although it is impossible to avoid a somewhat tedious description of this method, in practice it is quite easy, especially after a person has once succeeded.About the PublisherForgotten Books publishes hundreds of thousands of rare and classic books. Find more at www.forgottenbooks.comThis book is a reproduction of an important historical work. Forgotten Books uses state-of-the-art technology to digitally reconstruct the work, preserving the original format whilst repairing imperfections present in the aged copy. In rare cases, an imperfection in the original, such as a blemish or missing page, may be replicated in our edition. We do, however, repair the vast majority of imperfections successfully, any imperfections that remain are intentionally left to preserve the state of such historical works.