520 



NATURE 



{Sept. 29, 1 88 1 



prospectus, the work will be arranged according to subject?, and 

 not alphabetically. 



Nowhere, according to Prof. Porter, President of Queen's 

 College, Belfast, is the vital importance to the nation of tech- 

 nical education more keenly felt than amongst the merchants 

 and manufacturers of Ulster. " Germany " (observes the same 

 authority) "provides buildings, laboratories, and scientific appa- 

 ratus on the most liberal scale. In France, Belgium, Switzer- 

 land, and the United itates of America, higher technical educa- 

 tion is making rapid strides ur.der the fostering care of the 

 respective Governments, aided by the generous contributions of 

 patriotic citizens. The results of this wise liberality, while 

 enriching those nations, are most seriously affecting the manu- 

 facturing interests of this country, and especially of Belfast 

 and Ulster." Prof. Porter considers that in order fully to 

 develop the latent resources of that part of Ireland ve must 

 liave the means of giving young men a scieutilic training. 



In the BuUel'n of the Essex (U.S.) Institute for April, May, 

 and June is a paper by the Rev. G. F. Wright, on the Glacial 

 Phenomena of North America, and their Relation to theque-tion 

 of Man's Antiquity in the Valley of the Delaware. 



The additions to the Zoolot;icaI Society's Gardens during the 

 past week include two Bonnet Monkeys (Macaciis radiatus) from 

 India, presented respectively by Mr. J. Thompson and Mr. C. 

 Green ; a Macaque Monkey (Macacus cynomol^us) from India, 

 presented by Mr. W. Thomson ; a Banded Ichneumon (Her- 

 festis fascialtis) from West Africa, presented by Mr. W. Cubitt ; 

 two Common Otters {Luira iiili^aris) from Ross-shire, N. B., 

 presented by Mr. H. Mitchell ; a Black-crested Eagle (Lophoaelus 

 occipitalis) from Africa, presented by Mr. E. A. Harland ; a 

 Brush Turkey {Talegalla lathatm) from Australia, presented by 

 Capt. F. M. Burke, s.s. Oieybassa ; a Red-legged Partrirlge 

 {Caccabis nifa), European, presented by Mr. J. E. Clayton ; a 

 Common Cuckoo {Cuculus caiioriis), Biitish, presented by Master 

 Alfred Beart ; .an Americin Black ^ts.r (Ursus americanus) from 

 North America, deposited ; four Zebra Waxbills {Estrelda sitb- 

 flava) from Africa, purchased ; a Collared Fruit Bat (Cyito- 

 nycteris collarh), three Undulated Grass Parra', eets (Mdopsitlaais 

 undulatus), bred in the Gardens. The additions to the Insec- 

 tarium include larvrs of the Cojima Butterfly {Vanessa C, alburn)^ 

 scarce Swallowtail Butterfly {Papilio podaliriiis), and Privet 

 Hawk-Moth (Sphinx ligus/ii). Also iinagos of Jiaiialra linearis, 

 and a specimen of A/taais alias reared from larvte hatched in 

 the House. 



OVR ASTRONOMICAL COLUMN 

 The Satellites of Mars. — The approaching opposition of 

 this planet does not hold out much probability of satisfactory 

 observations of the satellites except with the larger instruments, 

 though in European latitudes the meridian altitude, which is an 

 element in the ca^e, will be considerable. Taking Prof. Asaph 

 Hall's unit for brightness in 1877, viz. that on October i, when 

 the outer satellite was seen w ith the 9'6-inch equatorial of the 

 Naval Observatory, Washington, we find the maximum bright- 

 ness at the next opposition will be represented by o'4, which is 

 a less value than corresponds to the last date of observation with 

 the 26-inch refractor at the same observatory. It may be re- 

 membered that Mr. Common observed Deimos on the morning 

 of September 2, 1879, without much difficulty with his reflector 

 of 3-feet aperture, when the degree of brightness in terms of 

 Prof. Hall's unit was 0*50 ; at the last Washington observation 

 in 1879 it was 0*52. The earth being only about 10° from the 

 line of nodes of the satellites' orbits at the opposition in Decem- 

 ber next, their apparent paths are reduced almost to straight 

 lines. The longitude of the ascending node of Deimos is 88°. 



The Satellites of Saturn. — Mr. Marth has again pre- 

 pared ephemerides of the five inner satellites of Saturn, which 

 have been published in the Astronomische NacJuichten ; he 

 appends differences of right ascension between the outer satellite, 



/apehis, and the centre of Saturn, but he does not attack 

 Hyperion. Preceding the ephemerides are auxiliary quantities 

 for every fifth noon at Greenwich, by means of which the posi- 

 tions of the five iiintr satellites may be determined for any time 

 required from the formula: — 



J sin (/>-P) = 3sin (/-L) 



J cos (/-P) = icos (/-L). 

 Here / is the angle of position with reference to the planet's 

 centre, and j the distance therefrom ; the values of (/— L) and 

 of the .'emi-axis a and b are tabulated for each satellite, as well 

 as the angle P, h hich is applicable to all five. The process is 

 simi le enough to any one initiated in such calculations, but as 

 there may be observers to whom they are unfamiliar, an example 

 may not Le out of place here. 



Let it be required to determine from Mr. Marth's tables the 

 an^le of fosition and distance of Mimas, at Greenwich mid- 

 night, on October I. We have then — 



(/-L) Oct. Id. oh. ... 287°-6o log « -fi'4Ss6 



Motion in I2h igr'04 sin (/- L) +9"9433 



/-L .. 



11 8° -64 Call the sum A ... -n-4289 



(P= 359°-58 

 From the tables •\a= 3o"'59 



log, 



•012S 



cos (/-L) -9-6806 



Call the sum B ... -f 0-6934 



sin(/-P) __!f__ 



•J 27"-3o 



The Fourth Comet of 1S74. — Dr. Holetschek, of the 

 Observatory of Vienna, has investigated definitive elements of 

 this comet, which was discovered on August 19, 1874, by M. 

 Coggia at Marseilles. He uses four normal pbces : for Augu,-t 

 21, September 18, October 10, and November 9. For the later 

 normals we presume he will have made use of a fine leries of 

 observations made v\ ith Cob Tomline's lo-inch refractor at the 

 Orwell Park Ob ervatory, near Ipswich, by Mr. J. I. Plummer, 

 w hich extends, we believe, considerably beyond observations 

 jiublishid so far from other observatories. With Col. Tom- 

 line's refractor the comet was followed until the middle of 

 November, and great tare appears to have been taken w ith the 

 observations and reductions. They form one of the very best 

 series that has obtained for some years at an English observa- 

 tory. Dr. Holet-thek infers that ihe comet was moving in an 

 elliplic orbit with a period of about 300 years. His orl^it is as 

 follows : — 



Perihelion Passage, 1874, July 17-68463, Greenwich M.T. 



Longitude of perihelion ... 

 ,, ascending node 



Inclination 34 7 54 



Excenti-icity 0-9622257 



Log. J erihelion distance 0-227275 



.Semi-axis major 44'67l 



Period of revelation 298-6 ye.ars. 



The co-J3et with these elements might approach pretty near to 

 the planet Uranus near the ascending node, but we might rather 

 look to an encounter v\ith Mars at the opposite node as the 

 cause of ellipticity of orbit, the radii-vectores being there iden- 

 tical, with but small difference of latitude. 



Ancient Star-positions. — In the Vierteljahrsschrift der 

 Astronomische Gesellsckafl, 16 Jahrgang, Dr. O. Danckwortt 

 has tabulated the positions of forty-six fundamental stars of the 

 Berliner yahrbuch for the commencement of each century from 

 - 2000 to -^ 1800. He adopts Leverrier's precession constants 

 for 1850, and takes account of the proper motions. The tables 

 are preceded by a discussion of formulse and comparison of 

 constants -which will be of service to any one who may have 



A%'^^-^^^^- 



