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THE PHOTOGRAPHIC NEWS. [February 27, 1891. 166 Motes. Mr. B. Harvey, in his letter from Kimberley last week, said in one line that the quagga is not extinct, and in another line that he “believes ” it not to be ex tinct. Since then we have had a letter from him, in which he says that he has written to all the newspapers in the Eastern Province of South Africa, to learn whe ther quaggas still exist. He also entertains the ambi tious idea of capturing one and sending it to Mr. Bart lett, the Superintendent of the Zoological Gardens, if anyone will pay expenses. If this animal—Beast, Mr. Harvey impolitely calls it, with a capital B—be not yet extinct, and the discussion which has arisen over the photographic frontispiece to the last Year-Book shall have been the means of the saving it, photography will have rendered one great service to zoology and to the world, and its votaries ought to keep a tame or wild quagga in memory thereof. Mr. Harvey might do worse than to send one live quagga to the Camera Club and another to the Photographic Society, to be kept as trophies on their new premises; a third might be sent to Messrs. York and Son. It is to be hoped that he will not ship striped jackasses of the wrong kind in mistake, so he cannot do better than to make all zoo logical or other suitable scientific societies in South Africa aware of the interest the subject has created in this country, and to get them to give the weight of their authority as to the existence or non-existence of the genuine quagga. The Count d’Assche sends us from Paris a copy of La Liberte, containing a long description of Professor Lippmann’s discoveries in heliochromy, but nothing more than has been already published in these pages. The writer of the article, however, called upon M. Nadar, and asked his opinion, as a professional photo grapher, upon the subject. The latter replied that it was an elegant and ingenious discovery, but not yet within the range of ordinary photographic work, chiefly because of the length of exposure, which, with plates of the sensitiveness at present employed by M. Lipp mann, varies from a half to two hours. M. Nadar gave his literary visitor much information about efforts to solve this problem in the past, and described to him the curious process with glasses of three colours which Ducos du Hauron and Charles Cros communicated more than forty years ago to the Academy of Sciences at almost the same time, and in almost the same words. Dr. Janssen, the president of the Permanent Com mittee of the International Photographic Congress, has written a letter, which appears in the last number of the Bulletin Beige, setting forth that the next meeting of the Congress will beheld in Brussels during the second fortnight in August next. The Committee asks the president of the Belgian Photographic Association to suggest subjects for inclusion in the programme of the next Congress. All communications about the Congress, Dr. Janssen says, should be addressed to M. S. Pector, General Secretary, 9, Rue Lincoln, Paris. We do not know to whom in Brussels letters should be addressed on the subject; beyond printing M. Janssen’s letter the Bulletin is silent on the subject. There is no doubt that if the Belgians think well to give a warm reception to the Congress, they will do it in a thorough manner. In the past we have seen much of their hospitality in this respect at Antwerp and other places. Photographers, like others, have had their share of troubles from the bursting of water pipes by frost during the late severe weather, and this has often interfered with work in the developing room. The remedy is to use oval instead of round water pipes, and such pipes are in the market. On freezing, water expands instead of contracts, and this bursts the pipes; the force ex erted is enormous; indeed, it was a favourite experi ment by Professor Tyndall at the Royal Institution to burst bomb-shells by the freezing of water in their interiors. Water in freezing renders the bore of an oval pipe more circular, and as the latter has a larger capacity than the oval form, the strain upon the metal is less than with ordinary pipes. Mr. Isaac Roberts, who has done so much valuable work in the field of astronomical photography, has contributed to the monthly notices of the Royal Astronomical Society a note on “Photographic evidence of Variability in the Nucleus of the great Nebula in Andromeda.” It seems that, during the past six years,, a large number of negatives were taken of this nebula,, the exposures varying from five to sixty minutes. In some of these the nucleus of the nebula seems to have: a decidedly stellar appearance, but in others quite a. different appearance is recorded. Mr. Roberts infers- from these different results in his photographic plates that the nucleus is variable. Another astronomical note which should be interest ing to photographers comes from Mr, Barnard, of the Lick Observatory, “On the Nebulosities of the Pleiades, and on a new Merope Nebula.” In November last Mr. Barnard, while examining the Pleiades, discovered a new and bright cometary nebula close south, and following Merope. This nebula has been constantly observed since that occasion, and its position has been determined, but it has not yet been photographed, owing to the fact that the long exposure required for the nebula would over-expose Merope to such an extent that the luminosity of the two would coalesce. We lately alluded to the bursting of a pressure gauge which was used in conjunction with a gas cylinder, and which, unfortunately, led to the serious injury of the person who happened to be handling it. Another accident of the same kind, but unattended by injury to anyone, has since been reported, and Mr. F. J. Smith, of Trinity College, Oxford, has sent some in teresting particulars of the occurrence to Nature. The
