The Optical Magic Lantern Journal (March 1892)

28 The Optical Magio Lantern Journal and Photographic Enlarger. Tue Parkinson Gas Co., of Manchester, recently gave a demonstration of their process of extracting oxygen from the atmosphere, by which oxygen in a high state of purity can be produced at a cost hitherto undreamed of. They propose to sell the plant and grant licences for working the process on royalty. 2 * cd AT achildren’s lantern entertainment held on the rgth ult., at the South St. Pancras LiberalUnionist Club, King’s Cross, a boy accidentally knocked over the lantern, when the oil from its lamp set fire to a small space, which, however, was promptly extinguished. Many in the hall were not even aware of the occurrence; but unfortunately some one cried ‘Fire!’ whereupon a general stampede ensued, and such was the rush for the staircase that about two dozen children fell on the stairs, and sustained injuries more or less severe. Several were conveyed to the hospital, and one little boy has since died from the result of his injuries. The others are progressing favourably. A New Combination Oxy-Hydrogen Microscope. Harpry has the last sound of the controversy over lantern microscopes died away, before we have another candidate for public favour in the shape of a combination lantern and table microscope. ; The accompanying illustrations clearly show the | microscope in its two positions. In Fig. 1 it is} adjusted for lantern use, and is shown with a portion of the draw-tube of the lantern attached. The large tube, bearing the maker’s name, carries at one end a parallelising lens, and at the other a standard size sub-stage condenser. The substage fitting, of course, permits of the use of a! Wenham’s parabloid, or any other piece of substage apparatus. The stage is of the ordinary pattern, but is furnished with an exceedingly useful object clip, which, by means of a spring, permits a thick live trough or a thin slide to be inserted with equal facility, and without scratching the labels. The objective is mounted in a special short tube, which is made to take an | one fitting and on to the other. amplifying lens if it is desired to protect the whole of a large object on a scale of any consider-+ able magnitude. The polariscope fittings are simple, but permits the operator to at all times ascertain the position of his Nicol prisms. he polariser is fitted between the parallelising lens and the sub-stage condenser, and can be given a complete revolution by means of a milled head on the outside of the tube. There is a stop so placed that the tube is rotated till it is reached; the prism is then adjusted and can _ always be brought into the same position, during use, by turning the milled head till arrested by the stop, The analyser fits into the front of the objective carrier, and is also capable of a complete rotation, an indicator on the fitting serving as a guide for the adjustment of the prism in this‘case as well. The conversion to a table microscope is instantaneous. The stage is made in two layers, one of which is attached to the body of the microscope, while the other, in duplicate, is fixed on the foot and lantern fitting respectively ; it is therefore only necessary to slip the body off The objective carrier is then removed and a draw-tube substituted, and all is ready for ordinary observations. It will be seen from the drawings that the coarse and fine adjustments are available for use in both : positions, although the latter is hardly necessary ‘for lantern work; for, the rack of the coarse adjustment being spiral, there is no “loss of time” while turning the milled head. All the working parts are compensated for wear, so that with proper treatment the instrument ought to last for a lifetime: At the present time, when almost every microscopist is also a photographer, it is desirable that a projection microscope should be adapted for photo-micrography, and it would be difficult to provide a better arrangement for the purpose than the one under notice. The objective may be used alone, in conjunction with a speciallyconnected amplifying lens, or with the draw-tube and eye-picce. The draw-tube being telescopic, is capable of taking any eye-piece in ordinary use, For the benefit of those microscopists who are not photographers, we may explain that it is