Feb. 17, 1876] 



NA TURE 



307 



Saturn's Rings. — In the last (January) number of 

 the "Monthly Notices of the Royal Astronomical So- 

 ciety" are reproduced some old drawings of Saturn, 

 given in the edition of Gassendi's works published at 

 Lyons, in six volumes, in 1658 (Lalande, Bibliographie 

 Astronotnique, p. 245), 



In the volume entitled De Annulo Safnrnt, by E. M. 

 Beima (Augsburg, 1842), a work less known in this 

 country than it deserves to be, will be found other repro- 

 ductions of the earlier drawings illustrating the appear- 

 ances which the planet was thought to present in the 

 imperfect telescopes of the time. As a pretty complete 

 monograph up to the date of publication, invohnng an 

 exposition of the formulas required in calculating the 

 various phases of the rings, &c., Beima's treatise will be 

 found a very desirable addition to an astronomical 

 library. 



The Minor Planet, Hilda (No. 153).— In Herr 

 Kiihnert's last orbit of this planet, the aphelion distance 

 is found to be 4'595, and the heliocentric latitude in 

 aphelion, — 6° 33', the longitude at this point being 

 105' i''6 ; hence, the least distance of the planet from 

 the orbit of Jupiter is reduced to 0*564 of the earth's 

 mean distance from the sun. So near an approach might 

 afford an excellent opportunity of determining the value 

 of Jupiter's mass, but if the period of revolution assigned 

 by Kiihnert upon eight-weeks' observations is at all ap- 

 proximate, such opportunity "will not occur for many 

 years to come. There may be a difficulty in recovering 

 this planet at the next opposition, which is likely to take 

 place near the aphelion, and when its faintness, owing to 

 great distance from the earth, will be considerable ; it is 

 the more desirable, therefore, that observations should be 

 obtained in the next period of absence of moonlight, that 

 the mean motion may be fairly determined this season ; 

 the Ephemeris published in No. 2,075 of ^^s Astrono- 

 mische Nachrichteti should render the identification of 

 the planet a matter of no great difficulty in instruments 

 of adequate aperture. 



From the resumi of observations in No. 42 of the Cir- 

 culars of the Berliner Astronotnische yahrbuch, it appears 

 that No. 149 may get adrift, unless an observation on 

 Nov. 2 can be proved to belong to it, and No. 155, as 

 already remarked, is in even worse position. 



The Total Solar Eclipse of 1706, May 11-12. — 

 Calculating upon the same system as employed for the 

 solar eclipses to which reference has already been made 

 in this column, the following elements result for the 

 eclipse of May 1706, extensively observed in France, &c. 

 Conjunction in R.A. 1706, May 11, 2ih. 59m. 26s. G.M.T. 



R.A 48* 40' 27" 



Moon's hourly motion in R. A 36 49 



Sun's „ „ „ 2 50 



Moon's declination 18 42 52 N. 



: Sun's „ 18 4 oN. 



Moon's hourly motion in decl 13 9 N. 



Sun's „ „ o 36 N. 



Moon's horizontal parallax 60 35 



Sun's „ ,, 9 



Moon's true semi-diameter 16 31 



Stm's „ „ IS 49 



The following are points upon the central track of the 

 adow : — 



Long. Lat. Long. Lat. 



5°4o^W. 34°39'N. ... i6» 32' E. 52* 23' N. 



I 4 E. 40 40 ... 20 2 E. 54 20 N. 



„ ( Central at Apparent Noon 



4 18 43 29 - •^ in Long. 29" 7' E. Lat 



7 37 46 12 N. ... j ^go jg-^j-/ 



For examining the circumstances of the eclipse in the 

 South of France, where the totaUty was witnessed, we 

 have the following reduction equations founded upon a 

 direct calculation for Avignon : — 



Cos. w = 41-1909 - [i-72si8] sin. / + [i "59372] cos. /, cos. {L - 103* 46^3) 

 t = 2ih. 26m. 5-85. T [2"o83S9] sin. ■»+ [3 '60351] sin. / 

 — [3-84024] COS. /, COS. \L + 38* i'-4). 



In these equations L is the longitude from Greenwich 

 reckoned positive to the eastward, I the geocentric latitude, 

 and / the Greenwich mean time of beginning or ending of 

 totality, according as the upper or lower sign is used. 



PROF. FLOWER'S HUNTERIAN LECTURES 

 ON THE RE LA TION OF EXTINCT TO EXIST- 

 ING MAMMALIA ^ 



I. 



IF no certain consensus has yet been arrived at as to 

 what palaeontology teaches in reference to the derivative 

 hypothesis, the chief reason is our very imperfect know- 

 ledge of palaeontology, arising partly from the necessary 

 imperfection of the geological record caused by the very 

 small chance of the remains of any creature living upon 

 the earth being preserved in a perfect state ; partly from 

 the ver)' minute portion of the record which is actually 

 preserved in the rocks having as yet been rendered acces- 

 sible to investigation ; partly from the defective know- 

 ledge of the structure and relationship of those documents, 

 so to speak, which have already been brought to light, 

 and of their existing representatives. The first cause must 

 always remain a stumbling-block to these investigations. 

 The second is gradually being removed by fresh explora- 

 tions in many parts of the world, notably those now carried 

 on with so much energy and success in North America. 

 The third is one which only needs more numerous and 

 more earnest workers to remove, and especially those 

 who have the power and will to see the continuity of the 

 manifestation of life upon the earth, and will abandon the 

 old practice of studying the fauna of a particular epoch 

 apart from that which preceded or succeeded it, and espe- 

 cially that of studying extinct forms without a thorough 

 mastery of the key to the solution of the difficulties of 

 their structure afforded by the more accessible existing 

 species. Palaeontology is no science apart — it can scarcely 

 even be called a branch of zoology ; it is simply the appli- 

 cation of that science to elucidating the structure of beings 

 now extinct The thoroughly unscientific and mischievous 

 system of arrangement of nearly all our great public 

 museums, both at home and abroad, where two distinct 

 collections are kept up, under distinct custodians — one 

 for animals existing at the present moment upon the 

 earth, and the other for animals that have existed at all 

 other periods put together — has much to answer for in 

 impeding the progress of sound zoological knowledge. 

 Granted that our information is of a very limited nature, 

 it still seems worth while occasionally to gather together 

 the fragments of which it consists ; and as it would be 

 impossible in the time allotted to this course to do justice 

 to more than a limited portion of the whole animal king- 

 dom, it is proposed to take the class of mammals, as in 

 many ways well suited for testing whether such facts as 

 are known of their ancient history throw any light upon 

 their mode of origin, and to point out, with impartiality, 

 the results of the investigation. The poverty of the mate- 

 rials in some quarters, as well as their abundance in 

 others, will thus be made manifest, and some useful land- 

 marks afforded which may direct and stimulate future 

 research. 



As far as we know of the existing fauna of the world, 

 and we can hardly suppose that in this respect our know- 

 ledge is not final, the Mammalia constitute a clearly 

 defmed group or class of the Vertebrata. Though covering 

 a wide range of variety in structure, scarcely any zoologist 

 has ever had any hesitation in defining its Umits. There 

 are, however, certain forms decidedly aberrant, and which 

 in many of the characters in which they deviate from the 

 ordinary standard of the class, approximate to the lower 

 groups of vertebrates. The most marked examples of 



I Abstract of a course of lectures delivered at the Royal College of Sur- 

 geons "On the Relation of Extinct to Existing Ma mm al i a, with Special 

 Reference to the Derivative Hypothesis," in condusion of the course of 1873. 

 (See Reports in Nature for tl^ year. ) 



