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January 30, 1891.] the photographic news. 87 turning apparatus had failed to act. A cavity had gradually formed in the cylinder, and had reflected the flame on to the upper part of the woodwork, which had taken fire in spite of its metal lining. Had the flame been reflected to a lower point the condensing lens would have been broken, for many have been fractured from a similar cause. The operator would do well to remember the advice which the bells of London seemed to whisper to a celebrated personage on Highgate Hill: “ Turn again, Whittington.” We need hardly add that the paucity of light was due to the same cause as the ignition of the lantern. Messrs. Marion are about to place on the market a new form of hand or detective camera, which is very novel in design, and which we hope to notice at length in a future number. But there is one novel point con nected with its manufacture which we think is of ex treme interest, and which will most probably point the way to doing work of a similar character. The most notable feature of the apparatus is a fan-shaped arrangement of metal grooves, in which the plates are stored. These grooves must be most carefully made in metal, and must each be correct in form to a hair’s breadth. They could not easily be stamped, and it was out of the question to make each one by hand, so the device was hit upon of producing them by the electrotype process in copper. From a suitable mould, these pieces of metal arc now produced at a compara tively rapid rate by use of the copper bath and a dynamo machine. We know of no other similar application of the electrotype process to the production of mechanical apparatus. A gentleman who was caught lately by the enlarge ment -for-nothing dodge, which has recently met with such ruthless exposure, and who forwarded a sovereign for the handsome frame required for the work of art, recounts his experiences in a provincial journal. He plaintively says that he submitted both portrait and frame to the unbiassed opinion of one or two artistic friends, and that, after mature con sideration, and after turning the portrait upside down, right-way-up, and sideways, so as to give it full advantage of varied positions, these judges came to the conclusion that there was nothing for it but to burn the dreadful thing to ashes, and it was then and there put behind the fire. Itwould seem that, occasionally, photography throws too much light upon astronomical observations; that is to say, it discloses the apparent existence of phenomena which might be misleading. Fortunately, there are so many astronomers working with photography in different parts of the world, that any mechanical error which has been set down as referring to some variation in the celestial body observed is readily detected. A case in point was brought before the notice of the Royal Astronomical Society at its last meeting. Some time ago Mr. Fowler, of the Observatory of the Royal Col lege of Science, South Kensington, thought he had discovered spectroscropic evidence of the duplicity of a Lyr, and a paper was read on the subject at the Society by Prof. Lockyer. It now turns out that, whatever may have been the cause of the doubling of this particular star, the cause is not to be found in the star itself. Prof. F. C. Vogel, of Potsdam Observatory, has taken eleven photographs of the spectrum of a Lyric since 1888, and in all these photographs the lines were perfectly sharp. Some of these photographs had been exposed during a period of forty minutes or more, and, if the observations at South Kensington had been correct, the changing separation of the lines during the period of the exposures ought to have caused them to appear blurred and confused, whereas they were perfectly sharp. Mr. Ranyard also brought forward evidence derived from an examination of photographs of the spectrum of a Lyras taken by the Bros. Henry, and had found the lines single and perfectly sharp. Mr. Ranyard suggested that the duplicity in the lines of the South Kensington photographs might be caused by the pinch ing of the prism in front of the object glass by a screw, which, if the strain were sufficient, would give rise to very sensible double refraction. Mr. Fowler, while admitting that, in the face of the facts brought for ward, a Lyrae could not be a double star, thought it was impossible that there could be sufficient strain ever put upon the prism at South Kensington to give rise to the double refraction Mr. Ranyard had sug gested. It now remains for the South Kensington astronomers to find out the reason of the apparent doubling in the photographs. The ordinary journalist, in writing upon photo graphic subjects, is, for want of knowledge, not very exact in terms, and hence unintentionally falls into blunders. For instance, we read in a contemporary that “the January number of The Chase contains another experiment in photographing in colours.” If this were really so, the wished for perfecting of a most important problem might have been reached. Of course, what the journalist meant to say was that the picture in question was a reproduction in colours from a pho tograph. The National Portrait Gallery is to be utilised at last, but in a way which will surprise most photo graphers. Green’s “Short History of the English People ” is to be issued in monthly parts, and a well- known engraver has been commissioned to make wood cuts of the National Portrait Gallery pictures, a task which will take three years at the least. How is it that these pictures cannot be photographed ? The time of photographing and preparing blocks, would be at least half that required by the engraver, the cost would be less, and of the accuracy there could be no doubt. Arc there any regulations which prohibit these pictures being photographed ?