Still another application of photography, becoming every day more and more familiar to the public, is that which produces enlarged portraits, even life-size ones, from the old daguerreotype or more recent photographic miniature.  As we have seen this process, a closet is arranged as a camera-obscura, and the enlarged image is thrown down through a lens above on a sheet of sensitive paper placed on a table capable of being easily elevated or depressed.  The image, weakened by diffusion over so large a space, prints itself slowly, but at last comes out with a clearness which is surprising,—­a fact which is parallel to what is observed in the stereoscopticon, where a picture of a few square inches in size is “extended” or diluted so as to cover some hundreds of square feet, and yet preserves its sharpness to a degree which seems incredible.

The copying of documents to be used as evidence is another most important application of photography.  No scribe, however skilful, could reproduce such a paper as we saw submitted to our fellow-workman in Mr. Black’s establishment the other day.  It contained perhaps a hundred names and marks, but smeared, spotted, soiled, rubbed, and showing every awkward shape of penmanship that a miscellaneous collection of half-educated persons could furnish.  No one, on looking at the photographic copy, could doubt that it was a genuine reproduction of a real list of signatures; and when half a dozen such copies, all just alike, were shown, the conviction became a certainty that all had a common origin.  This copy was made with a Harrison’s globe lens of sixteen inches’ focal length, and was a very sharp and accurate duplicate of the original.  It is claimed for this new American invention that it is “quite ahead of anything European”; and the certificates from the United States Coast-Survey Office go far towards sustaining its pretensions.

Some of our readers are aware that photographic operations are not confined to the delineation of material objects.  There are certain establishments in which, for an extra consideration, (on account of the difficilis ascensus, or other long journey they have to take,) the spirits of the departed appear in the same picture which gives the surviving friends.  The actinic influence of a ghost on a sensitive plate is not so strong as might be desired; but considering that spirits are so nearly immaterial, that the stars, as Ossian tells us, can be seen through their vaporous outlines, the effect is perhaps as good as ought to be expected.

Mrs. Brown, for instance, has lost her infant, and wishes to have its spirit-portrait taken with her own.  A special sitting is granted, and a special fee is paid.  In due time the photograph is ready, and, sure enough, there is the misty image of an infant in the background, or, it may be, across the mother’s lap.  Whether the original of the image was a month or a year old, whether it belonged to Mrs. Brown