PANORAMIC CAMERA. This is a form of Camera invented by the author, in which pictures may be taken upon one flat plate, including an angle of 90°, or more if required, without introducing the defects due to oblique pencils, such as distortion, indistinct ness, &c.
The following figure will, it is hoped, be intelligible with a few words of explanation.
The lens is mounted in a long narrow tube, or box, the same height as the camera. This revolves about an axis placed immediately over the stop. Inside the camera are placed two hoops, very strong and stout, one at the top, the other at the bottom of it. The dark slide always presses against these hoops. They are circular arcs, the centres of which are in the axis of rotation of the tube. The ends of the dark slide are furnished with wheels, which, as the slide is moved round, travel in grooves at the bottom of the camera, shown by the dotted lines. These dotted curves are evolutes of the lower circular hoop. The top of the lens tube is continued till it passes over the top of the upper hoop, and the bottom of the lens tube is continued till it passes under the bottom of the lower hoop, the dark slide is then placed between these projecting ends of the lens tube. A piece of wood lined with velvet is screwed to these ends, and, by pressing against the back of the dark slide, keeps it in its place against the hoops.
It is evident now, that as the lens-tube is turned about its axis, and directed in succession towards the different objects within the field of view, the dark slide moves with it, and is always pressed against the hoops, thus bringing the proper part of the sensitive plate opposite to the lens,—the velvet-lined piece of wood sliding at the same time against the back of the slide, and the wheels travelling along the evolutes.
The sides of the lens-tube are furnished with folding doors, so as to diminish, at pleasure, the width of the vertical band of picture exposed at any moment ; and its rotatory motion may be regulated by means of a rack and pinion on the top of the camera. The shutter of the dark slide may be withdrawn, and inserted again, either through a slit in the camera at A, or B. The mode of doing this may be left to the ingenuity of the reader.
The accuracy with which this novel instrument will do its work will depend upon the accuracy of its construction. The optical principles involve no difficulty, and the theory of the instrument is quite correct. All parts of the picture will be equally sharp, and vertical lines will not be bent out of the perpendicular. The per spective of the picture will, however, be " panoramic," and not " plane," so that the horizontal lines of objects will vanish in curved and not in straight lines. If this he thought an objection, the picture may either be mounted upon a bent cardboard, or bent round a glass cylinder, and viewed in a diaphanoscope, with the eye in the centre of the cylinder. Waxed paper prints, viewed in this way, would probably be finer than anything that has yet been seen in photography.
The panoramic camera will no doubt be found a valuable instru ment for taking skies.