208 



NATURE 



{Dec. 29, 1887 



new species oi Hyrax. Captain Shelley will contribute a paper 

 on the series of birds, which also embraces several new forms. 

 The Lepidoptera have been worked out by Mr. A. G. Butler, 

 and contain specimens of thirteen butterflies new to science, 

 Mr. Edgar A. Smith has examined the fresh-water shells which 

 Dr. Emin Pasha obtained on the Lake Albert Nyanza. They 

 are referable to five species only, but three of these, as might 

 have been expected from the novel locality in which they were 

 obtained, appear to be new to science. 



The Physical Society, of which Dr. Balfour Stewart was 

 President, was represented at his funeral by three of its 

 members : Mr. J. Johnstone Stoney, Prof. G. F. Fitzgerald, 

 and Prof. W. F. Barrett. 



In a lecture lately delivered by Sir Douglas Galton at the 

 Parkes Museum, he drew attention to the increase every year 

 of fog and smoke in London, and to the possibility of their 

 abatement. Dr. Russell's experiments, carried out at St. 

 Bartholomew's Hospital, for the Meteorological Council, showed 

 that the City rain contained twice as much impurity as that col- 

 lected in the suburbs. That is to say, if the City rain were diluted 

 with nearly an equal bulk of water, we should have the rain of 

 the suburbs. He referred to the experiments of Prof. Lodge 

 with a bell-jar filled with smoke, which is quickly deposited by 

 a discharge of electricity, and argued that by disturbing the 

 electrical condition of the air by kites or balloons, rain may 

 be caused, and by this means the fog dislodged. Failing this, 

 nothing remains but to use gas instead of open stoves, but this 

 method at present costs about four times as much as coal. 



We learn from the Annales Industrielles that a mine-shaft is 

 being successfully sunk by M. Alexandre, of the Houssu Com- 

 pany, in Belgium, through a stratum of moist sand 12 metres thick, 

 met with at 70 metres depth, by the Poetsch method, which 

 consists in freezing the sand, then excavating it like rock. In 

 the present case ten iron tubes (with cutting crown) are inserted 

 in the sand at about i metre interval, penetrating the coal below. 

 Into these are put other tubes, through which is passed a very cold 

 liquid to return by the larger tubes (generally chloride of mag- 

 nesium cooled by expansion of ammonia). The sand is frozen 

 more than 3 metres round the tubes. It has the appearance of a 

 rock harder than the compact chalk of the English Channel 

 tunnel ; it is sparkling, and speckled with particles of coal. The 

 chloride of magnesium, injected at - 14° C, returns at - 12°, 

 A thermometer inserted 10 centimetres in the stratum read -8°. 

 M. Poetsch's method was lately applied to making a tunnel at a 

 small depth under part of the city of Stockholm. 



Waterspouts are sometimes seen on the Lake of Geneva, 

 and M. Dufour has made a study of one which occurred on 

 August 19, about 7.30 a.m. {Arch, des Sciences). It seems to 

 have arisen on the lake at the meeting of two winds, one from 

 the south, in the eastern part of the lake, and the other from the 

 west, in the western ; and its path was along the line of demarka- 

 tion, changing direction somewhat as it neared the northern 

 shore. Some testified to a rising of the water, which was in 

 violent rotation (in the direction of the hands of a watch). The 

 base of the column was like whirling opaque smoke, which rose 

 in widening spiral, lost above in the cloud. The column was 

 considerably inclined, the upper part advancing more quickly 

 than the lower. In the rear was heavy rain. It is estimated that 

 the trombe was about 2 to 3 metres in diameter at foot, and 

 about 106 metres high, and its ra:e of progress about 760 metres 

 per minute (the speed of an express train). On reaching the 

 shore it disappeared, doing no h.irm either to vineyard or rail- 

 way, and had the look of a serpent drawing in its tail. The 

 weather was very variable that day, from hour to hour, and from 

 one part of the lake to another. There was no thunder nor 

 lightning. 



The United States Monthly Weathly Review for September 

 last shows nine depressions in the Atlantic Ocean, of which five 

 were of tropical or sub- tropical origin. Three advanced east- 

 wards from the American Continent north of 45° N., and one 

 appeared over the British Isles. Three of the depressions 

 moved across the Atlantic to Western Europe. As compared 

 with September 1886, there was a slight decrease in the quantity 

 of ice reported ; this year the northern limit was lat. 45° 37' N. , 

 and the eastern limit long. 40° 50' W. . 



The Port Officer of Madras has given notice, dated Septem- 

 ber 22, 1887, that the following storm-signals have been adopted 

 at the ports of the Madras Presidency, instead of the flags 

 hitherto used : — Day-signals : a ball indicates the probable 

 approach of dangerous weather ; a drum indicates that a cyclone 

 is likely to approach the port ; a cone, apex upwards, at the 

 flag-staff of the port, indicates that it is decided the shipping 

 shall be ordered to sea, . Night-signals : three lights, hoisted 

 vertically one above the other, indicate the probable approach 

 of dangerous weather ; two lights, hoisted vertically one above 

 the other, indicate that a cyclone is likely to approach the port ; 

 three bright lights, hoisted triangularly, one at the mast-head 

 and one at each yard-arm of the flag-staff of the port, indicate 

 that it is decided the shipping shall be ordered to sea. 



At the conclusion of the Colonial and Indian Exhibition some 

 specimens of the American lake-trout (6". namayctish), which had 

 been hatched and reared in the Canadian Section, were put in a 

 tank, where they prospered. One fish especially prospered, 

 surpassing the others in size by an inch. In the course of this 

 year they have all disappeared, with the exception of the one 

 referred to, whose colossal form accounts for its missing con- 

 geners, which evidently became its prey. Mr. W. August 

 Carter, of the National Fish-Culture Association, states that 

 about 50,000 of these fish were hatched at South Kensington 

 two years ago, when he observed them attack one another soon 

 after leaving their sac. There is a great diversity of growth 

 among them — greater than that which exists among British 

 trout. 



A CURIOUS incident is reported by Mr. William Burgess, pro- 

 prietor of the Midland Counties Fish-Culture Establishment. 

 He states that a pond constructed by him last March, measuring 

 - 50 feet by 30 feet, which is entirely isolated from other similar 

 ponds, was shortly after its formation found to be populated with 

 trout fry in their alevin stage. No fish of any kind had been 

 placed in the pond, and none could have entered it, the inlet 

 and outlet being blocked with perforated zinc of a very fine 

 mesh. The soil of the pond in question was excavated from a 

 brook where trout must have previously spawned, and the ova, 

 although buried in mud and flung heedlessly about, survived, and 

 the fry came to life when water had been let into the pond. 

 This is another proof of the enduring capacity of Salmonidcz ova. 



At a recent meeting of the Paris Biological Society, M. I>. 

 Vaillant offered some remarks concerning the way in which 

 Atitennarius marmorattis, a curious fish already studied by 

 Agassiz, builds its nest. Each nest is made of one sea-weed (of 

 the Sargasso Sea) the different twigs being brought together and 

 made fast to each other by the fish by means of a pasty sort of 

 substance provided by the animal itself. Agassiz thought that 

 separate bits of sea-weed were used, but it is shown that it 

 uses the whole of the twigs and branches of a single plant ; 

 which, of course, allows of much easier work. 



That the weasel {Mustela vulgaris) destroys frogs is proved 

 by the following incident. While standing near a pond on hi^ 

 estate, a gentleman at Worcester observed a weasel give chase to 

 a frog, which it followed to the water and succeeded in captur- 

 ing. Holding it firmly by the head, the weasel emerged from 

 the water and brought its victim to the bank, but on finding 



