'ng, 19, 1875J 



NATURE 



313 



is, - 2°*4, and in distance, - o""]\. The elements above are 

 perhaps affected by error of copy, but as they stand they 

 will admit of some improvement. 



With Dr, Duner's semi-axis and period, and Mr. Otto 

 Struve's first approximation to the annual parallax, the 

 mass of this system would be upwards of ten times the 

 solar mass. 



It will be remarked that the angles in the above orbit 

 arc expressed by Dr. Duner in decimals of degrees, and 

 we may take this opportunity of directing attention to a 

 very useful table of five-figure logarithms adapted to deci- 

 mals of the degree pubHshed at Berlin in 1872 by Dr. C. 

 Bremiker, which will be found available not only in 

 double-star computations, but very generally for five- 

 figure work. The figures closely resemble those in De 

 Morgan's well-known tables (which are now apparently 

 out of print), and consequently are exceedingly clear and 

 readable, and the price nominal (one shilling). Several 

 miscellaneous tables and various useful constants are 

 appended. The work will be sent over in paper cover, 

 and in binding this or any other set of tables for frequent 

 use, we would recommend the strong gilding of all the 

 edges as materially facilitating their working. When 

 shall we have a table oi four-figure logarithms to the 

 same extent as tables for five figures are usually printed ? 

 Such a work would be by no means without its value. 



(2) y Leonis.— Dr. Doberck, of Col, Cooper's Obser- 

 vatory, Markree, has calculated elements for this star, 

 though the arc described is at present less than 30°, 

 under which condition orbits widely different may be 

 obtained. Peri-astron passage, i74i'ii ; period of revo- 

 lution, 402'6 years; node, 111° 50'; X, 194° 22'; y, 

 43° 49' ; excentricity, 07390 ; semi-axis major, 2"'oo. 



There are several of the revolving double-stars of which 

 much better orbits than have yet been published might 

 now be found ; as, for instance, w Leonis and a Ophiuchi. 

 Of the fairly determined orbits, the shortest period 

 appears to be that of 42 Comae Beren — 25*5 years, 

 according to Mr. Otto Struve ; and the longest that of 

 Castor, 997 years, according to the very complete inves- 

 tigation of Herr Thiele. 



The Minor Planets.— M. Leverrier, in his "Bulletin 

 International" of the 8th inst., announces the discovery of 

 No. 148 at Paris, by M. Prosper Henry, on the same 

 morning. The planet is of 107 mag., and was found a 

 little west of 70 Aquarii. — Circular No. 31 of the " Berliner 

 Jahrbuch" contains new elements of Lachesis (120) ; the 

 period of revolution at the next opposition in November 

 is 2,028 days. In No. 30 appeared new, though still 

 uncertain, elements of Austria (136) ; period 1,261 days. 



The August Meteors.— The extensive systematic 

 plan of observation at the principal meteor epochs which 

 has been for some time organised by the Scientific Asso- 

 ciation of France, at the instance of M. Leverrier, has 

 again been attended with success, on the occasion of the 

 Perseid shower. At Rouen on August 9, between iih. 

 and I5h., 200 meteors were noted, of which 180 came 

 from the Perseus-radiant ; at Rochefort, on the same 

 night, 258 meteors were observed, nearly the whole con- 

 formable ; and on the nth, at the same place, 260, many 

 with the same radiant. — About August 5th, in the neigh- 

 bourhood of London, an unusual number of meteors, 

 more than one as bright as stars of the first magnitude, 

 diverged from Omicron in Andromeda. 



Prof. Oppolzer's definitive elements of Comet 1862 

 (III.), with which the August meteor-stream is associated, 

 are here subjoined : — 



rerihelion passage, 1862, August 22-91192 G.M.T. 



Longitude of perihelion ... 344° 4j' 32" j m. Eq. 1862-0 



Ascending node ... 

 Inclination to ecliptic 



Eccentricity 



Semi-axis major 



Period of revolution 



137 27 10 

 66 25 48, 

 0*9607588 



24'53i42 

 121*502 years. 



The point of nearest approach to the earth's orbit at 

 i the descending node is passed I9"357 days after peri- 

 j helion ; if in 1862 the comet had arrived af perihehon 

 I July 21-557, a little before noon on the loth of August, it 

 would have been distant from the earth less than twice 

 the distance of the moon. It might not be without inte- 

 rest to determine the effect of so close an approach to our 

 globe, upon the orbit of the comet ; but in such an 

 unusual computation it appears almost necessary that 

 earth and moon should be treated as distinct disturbing 

 agents ; perhaps the ordinary methods might apply, if the 

 intervals were taken sufficiently short and the elements 

 changed with sufficient frequency. 



THE SEPARATION OF THE ARAL AND THE 

 CASPIAN 



T N a note on the Hyrcanian Sea (vide Nature, vol. xii., 

 •*• p. 51), it was stated that the waters of Aral, whose 

 surface is now about 159 feet above sea level, formerly over- 

 flowed at their S.W. corner, when the lake possessed a 

 depth of 50 feet more than at present. It is certain 

 that the spur of Ust Urt, which formed a waste weir at 

 the point in question, has been lowered by the action of 

 escaping water ; and the level at which the overflow took 

 place, in the first instance, was probably some few feet 

 higher than the figure of 209 which has been given. The 

 greatest height ever reached by the water contained in 

 the basin of Lake Aral may therefore be said with toler- 

 able accuracy to be about 220 feet above the sea. 



On the N.W^., near the head of the Tchagan stream, 

 where Aral must have overflowed to flood the country 

 round the limits of Ust Urt, the barometrical height of a 

 point situated in latitude 47° 7' 27", and longitude (east 

 from Greenwich) 58° 17' 41", is 257 feet (<?). This height 

 approximates sufficiently to that which has been indicated 

 for the overflow at S.W., to suggest that future levelling 

 operations will find a point somewhere in this neighbour- 

 hood situated at less than 220 feet above the sea. There is, 

 in addition, in latitude 43° 1 5', a cleft in the eastern cliff of 

 Ust Urt, by which, and probably by other similar clefts 

 yet to be discovered, the waters of Lake Aral may have 

 overflowed to the west ; and in such a case they would, 

 as they travelled down to the lower level of the Caspian 

 Sea, have submerged many extensive, depressed tracts, 

 which occur on the surface of the intervening country. 

 The separation of the two seas, which has afforded 

 subject for much discussion, seems thus actually to have 

 been due to the cessation of the overflow of the basin 

 upon the higher level. Nor is, perhaps, that separation 

 so entirely complete as has generally been thought, for 

 Lake Aral could possibly be filled and made to overflow 

 again ; and under such restored conditions, the physical 

 aspects of the country lying between the two seas v/ould 

 very nearly resemble those which are possessed at the 

 present time by the country on the lower courses of the 

 Amu Darya, and are caused by the annual flooding from 

 that river. In such a drowned condition, the Aralo- 

 Caspian region was naturally included in the water-spread 

 of the Hyrcanian Sea by all the classical historians and 

 geographers who have described it ; and though, perhaps, 

 no possible overflow from Lake Aral could now exactly 

 reproduce the physical aspects of 2,000 years ago, such 

 difference as would be observable is susceptible of expla- 

 nation by considerations to be presently entered upon. 



Since the accidental circumstance of more or less 

 water having existed in several depressions upon the surface 

 of the Aralo-Caspian region is the only known variation 

 which has attached to its physical aspects from the earliest 

 historical times, there is a strong presumption that no 

 phenomena of upheaval have occurred, and that over- 



(d) These figures are taken from the Catalogue of Trigonometrical and 

 Astronomical points in the Russian Empire. Edited by the Director of the 

 Geodesical Department of the Military Topographical Staff. 



