March, 1907.] 



KNOWLEDGE & SCIENTIFIC NEWS. 



In connection with the concluding part of the last 

 sentence, it should be mentioned that reptiles, like 

 fishes, but unlike birds and mammals, continue to grow 

 throughout their entire span of life, so that unusually 

 large bodilv size is, at all events as a rule, an indication 

 of advanced age. As regards general appearance, 

 Triceratops may, perhaps, be best described as a rep- 

 tilian rhinoceros, with the proviso that the tail was 

 much larger and thicker than in that group of animals, 

 and passed insensibly into the body, as in reptiles gener- 

 ally, while the number and arrangement of the horns 

 were different. 



To imagine what colour the creature may have been 

 in life is, of course, mainly, if not entirely, a matter of 

 pure conjecture. From the prevalence of slaty huts 

 in giant living mammals of the present day, such as 

 elephants, rhinoceroses, and hippopotamuses, Professor 

 Lucas is, however, inclined to believe that similar tints 

 may have obtained among the giant reptiles of former 

 days. "So," he writes, "while a green and yellow 

 Triceratops would undoubtedly have been a conspicu- 

 ous feature in the Cretaceous landscape, from what we 

 know of existing animals, it seems best to curb our 

 fancy, and, so far as large dinosaurs are concerned, 

 employ the colours of a Rembrandt rather than those 

 of a sign-painter." 



As already mentioned, the head of the Triceratops is 

 so vast in proportion to the rest of the animal that it 

 might seem a difficult problem in mechanics to explain 

 bow it was adequately supported in life. The solution 

 of the problem, according to the researches of the 

 American palaeontologists, is apparently to be found in 

 the great posterior fringe of the skull, which served 

 not only as a means of defence, but acted as a counter- 

 poise to the enormous weight of the fore-part of the 

 skull, and likewise afforded ample space for the attach- 

 ment of the mass of muscles and ligaments necessary 

 to support and move the enormous head. As a matter 

 of fact, the centre of gravity of the skull has been 

 found to be situated behind the eyes, so that the head 

 was well balanced on the anterior neck-vertebra'. It 

 may be added that, as in whales, several of the vertebrae 

 of the neck were more or less completely welded to- 

 gether so as to afford additional support and stability 

 for the attachment of the muscles. Of course, this 

 implies restriction of mobility in the neck, but as this 

 was already brought about by the existence of the oxer- 

 hanging frill itself, no additional detriment was in- 

 volved. = ==^= 



The Observation of Meteors and 

 Meteoric Showers. 



By \V. F. Denning. 



THERE is SO much to be said with regard to this sub- 

 ject that it can hardly be comprised within the limits ol 

 a short paper. If photography could now effectually 

 take tin- place of visual observation we might luck for 

 more accurate results, but, unfortunately, we still have 

 to depend mainly upon rough eye estimates of position. 

 It will be important to determine « hether tin- Ho. a ids. 

 Aquarids (May and July), Leonids, Geminids, and sonic 

 other rich Streams, exhibit a shitting or fixed radiant. 



Tin' I'erseids and Lyrids have centres becoming dis- 

 placed from night to night, while tin- Orionids form a 

 stationary radiant. 



Fresh evidence should be gleaned as to the apparently 

 long duration of a greal number ol minor systems ami 



the unchangeable situation of their radiant points. Aie 

 the latter identical in position during their prolonged 

 activity? 



The principal periodical displays should be observed 

 from year to year, and the date, hour, and visible 

 strength of their maxima carefully noted. 



Do the Andromedids form an annual display simi- 

 larly with the Perseids, Leonids, &i . ? 



Fireballs should be precisely and fully recorded 

 whenever they are seen, both as to their paths amongst 

 the stars and the durations of their flights. These 

 brilliant objects are usually directed from radiants in 

 the western half of the sky, and move slowly in orbits 

 overtaking the earth. As they often appear at times 

 when regular meteoric observers are not watching the 

 heavens, astronomers generally should combine to re- 

 cord and communicate the necessary data for the com- 

 putation of their real paths in the air. 



I have often thought it would be a good plan to form 

 a society specially devoted to the observation and dis- 

 cussion of fireballs. The society need simply consist 

 of gentlemen who would undertake to record and re- 

 port such large meteors as they see either casually or 

 during regular observation. These objects are some- 

 times not fully recorded, and many are not publicly 

 notified at all. Thus numbers of them escape suitable 

 investigation every year in England alone. If observers 

 made it a practice of supplying prompt, ample, and 

 accurate information of such conspicuous meteors as 

 they witnessed, the materials would soon form a sub- 

 stantial gain to meteoric astronomy. 



For the detection of the ordinary shower-radiants of 

 shooting stars individual observers are recommended to 

 pursue long watches habitually. The great majority 

 of meteoric showers are so feeble that they will escape 

 n cognition unless the search for them is very keen and 

 pei severing. A single observer is capable of doing a 

 great deal of useful work, but must, necessarily, do it 

 in a very thorough manner, or the data secured is 

 sure to be meagre. But an experienced and naturally- 

 talented man will certainly derive more exact and trust- 

 worthy results than any combination of individuals. 

 One amongst the latter may lie very inaccurate, and 

 the incorporation of his results will spoil the whole 

 collection. In a cloudy climate like England, however, 

 an observer working single-handed cannot achieve 

 much, but it is astonishing how many materials can lie 

 gathered by a person who watches during the whole 

 night and avails himself of every opportunity presented. 



It is particularly with regard to fireballs that I trust 

 some effort will soon be made to secure more numerous 

 observations. The necessity lor this will be obvious 

 when I mention that during the last three months of 

 roo6 I received, or read published, descriptions of 45 

 large meteors seen in England. Yet only in three or 

 four eases were duplicate observations forthcoming. 

 If some organised plan were followed in collecting data 

 concerning fireballs I feel certain that instead ol some 

 half-a-dozen of their r< al paths being computed annually 

 we should soon be in a position to increase the number 

 to 30 or 40, and this would represent a very important 

 addition to this interesting branch of science. 



Planetary Chart for 1907. 



Messrs. Cari Zeiss send a sheet containing particulars of 

 tnetarj positions prepared from the specification of 

 R, 11. Bow, ol Edinburgh. Two charts are presented, one 

 showing the declinations at any given date, the other iie,ht 

 ascensions. [laving found the R.A. and Decl. for an) date 

 from these two curves, the place ol the planet is then plotted 

 <m the zodiacal star chart at the top ol the sheet, li 



»'. a considerable amount of useful information in a 

 small space, and will doubtless be convenient to many who 

 ha\ e not tables handy. 



