NATURE 



[January 19, 1905 



Ephemeris for Comet Tempel, 1904 c. — In No. 3986 of 

 the Asironomischc Xachriclitcn M. J. Coniel g^ives a daily 

 pphemeris for Tempel's second comet extending from 

 January 3 to March 2, which is a continuation of the 

 ephemeris published by him in No. 3971 of the same 

 journal. Although the southern declination of the comet 

 is decreasing, its R..-\. is so near to that of the sun, and 

 the object itself is so faint, that observations will be 

 difficult, and only possible immediately after sunset. 



The comet's position on January 21 will be 



R.A. = 22h. 37m. 47s., dec. = — 16° 19'. 



Se.vsonal Develop.ment of M.\rthn Canals. — A further 

 contribution of observed phenomena, in support of his 

 theory concerning the causes which produce the seasonal 

 development of the canals on Mars, is published by Mr. 

 Lowell in the January number of Popular Astronomy. 

 The particular canal therein discussed is Brontes, which 

 is 2440 miles in length and connects along a great circle, 

 in nearly a north and south direction, the two iijiportant 

 points Linus Titanum and the Propontis. 



From a study of ninety drawings made during the 

 period Januarv-Julv, 1903, six of which are reproduced 

 on the plate accompanying the paper, it was seen that 

 the visibility of the canal increased after the summer 

 solstice in the northern hemisphere, and, further, on 

 dividing the canal into five nearly equal sections from 

 north to south, the section nearest the north polar cap 

 became strengthened first, and the others followed in order 

 of their north polar distance. This is plainly shown on 

 the visibility " cartouches " given by Mr. Lowell, who 

 considers the phenomena as a further proof of his theory 

 that the visibility of a canal is due to vegetation, quickened 

 by the water loosened at the melting of the polar snows 

 and flowing towards the equator. The extension south of 

 the equator is considered as a probable proof of intelligent 

 artificial interference in the propulsion of the water. 



Variable Stars and Nebulous .\reas in Scorpio. — An 

 examination of thirty-three plates exposed on the large 

 nebulous regions mentioned in previous Circulars has led 

 Miss H. S. Leavitt to the discovery of 105 new variable 

 stars in the constellation Scorpio. 



The positions of these, for 1900, their greatest and least 

 observed magnitudes, and their magnitude ranges are 

 given in No. 90 of the Harvard College Observatory 

 Circulars. 



The most striking result of this research has been the 

 revelation of vast areas of diffused nebulous matter, so 

 faint as to be beyond visual observation. One of these 

 areas extends over a number of square degrees in the 

 constellations Ophiuchus and Scorpio, and, like the Orion 

 nebula, it attaches itself to individual stars, the principal 

 condensation being about the quadruple star p Ophiuchi. 

 The region is marked by an absence of faint stars, and 

 dark lines may be traced beyond the confines of the 

 nebulosity as yet seen on the plates. 



Report of the Natal Observ.atorv. — The report of Mr. 

 E. Nevill, Government astronomer of Natal, for the year 

 1903, gives a brief resume of the work accomplished at 

 the Durban Observatory during the period with which 

 the report deals, and contains a mass of information 

 respecting the meteorology of the colony. 



The time signals have been sent out as in former years, 

 and Borrelly's comet was observed regularly during its 

 appearance, the orbit deduced from the observations agree- 

 ing with those obtained at other observatories. 



It is proposed to utilise the tide observations made 

 during the years 1S84-8 in order to provide the port 

 authorities with tide-tables, but, owing to the construc- 

 tional changes in the harbour during the last few years, 

 it will be necessary to reduce the more recent observations 

 and this will require additional computing assistance. 



In former years it has been customary to issue the 

 meteorological data compiled from the returns of the sub- 

 sidiarv stations once each mcjnth, bpt in future the returns 

 will be published daily. .Vmong the numerous tables 

 given in the report there occurs, for the first time, a 

 summary of the meteorological observations made at the 

 Botanical Gardens, Durban, during the period 1873-1883 



NO. 1838, VOL. 71] 



inclusive, before the institution of the (iovernment 

 observatory. 



The Jesuit Observatory at Belex, H wana. — .An 

 interesting illustrated account of the observatory attached 

 to the Jesuit College at Belen, Havana, has been written, 

 in .Spanish, by Father Mariano Gutierrez, .S.J., the sub- 

 director, and contains a history of the installation of the 

 institution in 1857, and its proceedings since that date. 



The meteorological section was first founded under the 

 direction of Father .Antonio Cabr^, S.J., in the year 

 named, but its position was not secured until the in- 

 stallation of Father Vines as director, in 1870, to the 

 memory of whom the author of the history pays a high 

 tribute, and laments his death in 1893 as an irreparable 

 loss. 



The equipment of the observatory is fairly complete, 

 and includes meteorological, seismological, magnetic, and 

 a.stronomical instruments, most of which, including the 

 6-inch Cooke equatorial, are illustrated in the present 

 volume. 



THE DISCOVERY OF JUPITER'S SIXTH 

 S. ATE LUTE. 



T^HE addition of a sixth satellite to the system of 

 Jupiter marks another triumph in Prof. Perrine's 

 employment of the modified Crossley reflector. .As 

 mentioned in a note published in " Our .Astronomical 

 Column " last week. Prof. Perrine first suspected the 

 existence of the newly discovered body from observations 

 made during December, 1904, but it was not until 

 January 4 that a further observation confirmed his 

 suspicion, and enabled him to open the new year with 

 the announcement of this important discovery. 



The new satellite, so far as one may gather from the 

 meagre news yet to hand, is situated at a much greater 

 distance from its primarv than any of the five previously 

 known. The telegram announcing the discovery gave this 

 distance, on January 4, as 43', whilst that of the outer- 

 most of the four satellites discovered by Galileo never 

 exceeds 10' -5, and the fifth, the innermost of all, is not 

 quite half the distance from Jupiter that the moon is 

 from the earth. 



.Assuming, for the moment, that the above distance is 

 the outward limit of the satellite's orbit, it should make 

 one revolution about its primary in about half a year, 

 whereas the time occupied by the fourth satellite is only 

 167 days; thus we see there is an immense gap between 

 the two bodies which, according to precedent, may contain 

 other satellites as yet undiscovered. 



The recent discovery raises the number of satellites in 

 the solar system, discovered during the past thirty years, 

 to five, and it is worthy of note that the discovery of 

 a satellite has usually occurred at times when a new 

 instrument has been installed or old instruments or methods 

 have been improved. This fact calls to mind, although 

 bevond our thirty years' limit but still dealing with the 

 Jovian system, that Jupiter's four moons, lo, Europa, 

 Ganymede, and Callisto, or i., ii., iii., and iv. as they 

 are usually designated, were the first members of the 

 solar system to be discovered, resulting, as they did, from 

 Galileo's first use of the telescope in January, 1610. 



.After these, and within the past thirty years, came 

 Deimos and Phobos, the lilliputian attendants to Mars, 

 which were discovered by Prof. .Asaph Hall at Washing- 

 ton in August, 1877, and were the first fruits of the then 

 recently mounted 26-inch refractor of the U.S. Naval 

 Observatory. 



The fifth satellite of Jupiter was discovered by Prof. 

 Barnard on September <». 1S92, with the nearly new- 

 giant refractor of the Lick Observaton, . It is, com- 

 parativelv, a minute object and can only be seen with 

 the largest telescopes under the most favourable con- 

 ditions. Its diameter can scarcely be greater than 100 

 miles, whilst the diameters of the other four, in order 

 of their distance from the planet, are 2400, between 

 211CH) and 2200 (about the size of our own moon), 3000, 

 and 3600 miles respectively. This object revolves between 



