Dec. 30, 1875] 



NATURE 



173 



pipes, that if we remove the whole of the skins or sides of pipes, 

 which separate fluid from fluid ar.d which are all therefore neces- 

 sarily in perfect equilibrium, the forces acting on the remainder, 

 namely, on those skins which are in contact with the surface of 

 the body, forces which therefore may be considered as acting 

 simply upon the body, must also have no endways sum totaL 



THE MELBOURNE OBSERVATORY 

 'T'HE Board of Visitors to this Observatory made its annual 

 ■*■ visitation on June 2, 1875. ^I''- EHery, the Government 

 Astronomer, having obtained leave of absence, the Board 

 found the staff" of officers and all the instruments in charge of 

 Mr. White, in whose management it unhesitatingly expresses its 

 fullest confidence. 



The buildings and instruments are in good condition, and 

 several new and important instruments have been added to the 

 establishment during the period under notice. These include a 

 photo-heliograph from Dallmeyer, of London, who constructed 

 it under the advice of Dr. Warren de la Rue ; an equatorial 

 refractor of eight inches aperture, made by Troughton and Sims, 

 under the ad\ice of Sir George Airy ; a portable equatorial, of 

 44 inches aperture, by Messrs. Cook and Son, of York ; and a 

 double-image micrometer by Mr. Browning. 



The various publications of the Observatory are in a forward 

 condition. The First Melbourne General Catalogue of 1,227 

 Stars, for the epoch 1870, was published early in October, in 

 time to be distributed among the different parties charged with 

 the observation of the transit of Venus, by whom its great utility 

 was acknowledged. 



The observatory staff" had much work to do in connection with 

 the observation of the transit of Venus, not only having to make 

 the necessary preparations for observing the transit at their own 

 stations, but also to assist with the requisite observations for 

 finding the positions of the stations occupied by the different 

 nations in that part of the world. The arrangements made by 

 the Obser\atory were all that could be desired. 



With regard to the ordinary work of the Observatory, Mr. 

 Wliite reports as follows : — 



" The work with the transit circle has consisted of the usual 



standard stars for finding the time, and the position of the instru- 



I ment ; close circumpolar stars, low stars for refraction, stars with 



I which bodies had been compared off" the meridian, stars culmi- 



1 nating with the moon, the moon itself, and stars whose places 



were required by outside observers for any special purpose. 



i " The numbers of the recorded observations are as follows :--• 



' R.A. observations, 2,064; PD. observations, 1,150; Observa- 



\ tions of error of collimation, 1 1 1 ; observations of error of level 



and nadir, 180 ; observations of error of runs of microscopes, 



47 ; observations of error of flexure, 35. 



" The state of the reductions is as follows : — 



" R.A. observations up to date. 



" P. D. observations. — The stars observed in 1873 are reduced 

 with the exception of 212, which require the corrections to reduce 

 them from their apparent to their mean places. Of the stars 

 observed in 1874, 865 are wholly unreduced, 267 have the reduc- 

 tions applied as far as the refraction, 45 are reduced to their 

 apparent places, and the remaining 45 are fully reduced. Of 

 the stars observed during the present year, 184 are fully reduced, 

 46 are reduced to their apparent places, and 122 are wholly 

 unreduced. . . . 



"The magnetical and meteorological instruments are under 

 the special charge of Mr. Moerlin. Absolute values of the msg- 

 netic elements have been made as usual once a month, and they 

 are all reduced up to date. The photographic curves from the 

 magnetographs, barograph, and thermographs, are developed on 

 every alternate day, but as yet no general tabulation of them has 

 been made ; only occasional measures are taken from them for 

 special purposes. The ordinary meteorological observations 

 made at Melbourne and the diff"erent stations in the colony are 

 reduced to date ; the Monthly Records in Meteorology and 

 Magnetism are prepared to the end of April, and are in the 

 printer's hands ; owing to press of work, however, in the 

 Government Printing Office, the Records to the end of December 

 1874 oiily have as yet been received. The Yearly Report for 

 1873 is in hand, and that for 1874 will be prepared as soon as 

 possible. 



" The great telescope, under the especial charge of Mr. Turner, 



has been diligently worked during the last twelve months, 



, I except during the time that we were engaged in the special ob- 



I 



servations connected with the transit of Venus, when Mr. 

 Turner took turns with Mr. Moerlin in observing the occultation 

 of stars by the moon. In accordance with the strongly ex- 

 pressed opinion of the Board in the last Report, the work done 

 has consisted principally of drawing the nebulae, and mapping 

 the neighbouring stars ; ten of the nebulae and clusters fiipired 

 by Sir John Herschel have been carefully drawn, and the posi- 

 tions of the stars have been laid down from micrometric measure- 

 ments. One nebula has been observed which is not to be 

 foimd in any catalogue in our possession. Coggia's comet was 

 examined on eighteen nights, and fifteen drawings of it ob- 

 tained. A drawing of the nebula surroimding rj Argus, with 

 the stars accurately plotted in, made this year, shows no appre- 

 ciable change when compared with the one made last year. 



" Besides the occultation of stars by the moon, referred to 

 before, and of which ninety-six were looked out /or, and only 

 fifteen observed, owing to the tmfavourable weather of the time, 

 a fine series of observations for positions of Coggia's comet was 

 obtained by Mr. Ellery and myself ; an observation of Encke's 

 comet was also obtained during the present month ; all of which, 

 including the occultations, have been sent for publication to the 

 Astronomische Nachrichten." 



The Report concludes with a brief account of the results ob- 

 tained at the four Government stations during observations of 

 the transit of Venus. 



PROF. PARKER ON THE WOODPECKERS 

 AND WRYNECKS 



A NOTHER admirable paper by Prof. Parker, exhibiting the 

 "'"*■ same industry, successful elucidation of detail, and mastery 

 of morphological principle that have characterised all his publi- 

 cations, appears in the recently-issued volume of " Transactions 

 of the Linnean Society." It is chiefly devoted to an exposition 

 of the palatal structures of the Picidae and Yungida;, made intel- 

 ligible by the study of nestlings and young birds. The conclu- 

 sions of Prof. Huxley in his paper in the " Proceedings of the 

 Zoological Society" for 1867 are substantiated and placed on u 

 broader basis ; and thereby another chapter has been permanently 

 added to the history of the connection between Reptiles and 

 Birds. The assistance which scientific naturalists all over the 

 world may render to necessarily sedentary students like Mr. 

 Parker, by the preservation and transmission of young specimens 

 of various ages, is nowhere more clearly manifested than in the 

 paper now spoken of. Mr. Parker's study of Woodpeckers, 

 both of hard and soft parts, dates from the year 1S43 ; and the 

 unpublished results of that labour, in the form of minutely- careful 

 drawings, are still of considerable value for reference. Again 

 and again the study was resumed, with somewhat unsatisfactory 

 results, until the opportunity of dissecting young birds and of 

 comparing them with southern species threw sufficient illumina- 

 tion on the difficult problem of their palatal structure. 



An introduction to the paper scr\-es to point out the proper re- 

 lations between the zoologist and the embrjologist. "Each kind 

 of labourer," says Prof. Parker, "has the greatest need of the 

 results brought out by the other : the patient dissector waits for 

 the treasures supplied to him by the more mercurial taxonomist ; 

 whilst he, in turn, profits by the work of one to whom a single 

 type may serve for the labour of a year or more. Yet both are 

 learning to look beneath the surface of things, a growing know- 

 ledge of the types showing both that close kinship is often 

 marked by great difference in outward form, and that it is easy 

 to be beguiled by the external likeness of forms — isomorphic, 

 indeed, but far apart zoologically." 



A defence is made against those who would accuse the author, 

 as well as Prof. Huxley, " of taking a narrow view of the bird- 

 types, touching with the point of a needle some little tract, but 

 unacquainted with and not able to appreciate the Bird as a 

 whole." Such an accusation charges the broadest-minded men 

 with possessing a cast of mind which would utterly disquahfy 

 them for the distinguished positions they hold. In the present 

 case the exclusive description of the palatal structures is easily 

 defended : for " that territory contains parts that have undergone 

 the greatest amount of metamorphosis of any in the whole body 

 of a high and noble vertebrate ; and moreover, being in the bird 

 the skeletal framework of the whole upper face, these parts are, 

 as it were, an index of the amount of specialisation undergone 

 by any particular type — the ruling determining structures that 

 lead to all, and really demand all, the changes that take place 

 in the rest of the oi^anism." 



