96 



KNOWLEDGE & SCIENTIFIC NEWS. 



[May, 1904. 



transits. The photographic plate must be made to travel 

 if the registration is to be extended to the fainter stars, and 

 the rate of motion should vary with tlie declination of the 

 star. The suggested solution would place the object glass of 

 the transit instrument in its horizontal axis, and the photo- 

 graphic plate would travel on the arc of a circle, the centre of 

 which coincided with the centre of the object-glass. This arc 

 would be carried by a polar axis, the prolongation of which 

 would pass through the centre of the object-glass. If the 

 polar axis were driven uniformly by clock work, as in the 

 ordinary equatorial, the plate would always move at the 

 pniper rate for the declination of the star to which the tele- 

 scope was pointed, and would .ilways lie in the focus of the 

 transit telescope. 



* ♦ ♦ 



Burnham's Mea.sure of Double Stars. 



.•\mongst the decennial publications of the University of 

 Chicago is a memoir by Frnfessor S. W. Biirnham on his 

 " Measures of Double Stars," made with the 40-inch refractor 

 of the Verkes Observatory in igoo and igoi. The memoiris 

 one of very great importance, because the work undertaken 

 by Mr, Burnham was the re-observation of stars which had 

 been neglected, in most cases entirely, for some seventv or 

 eighty years. The majority therefore are wide, or verv wide, 

 pairs, and could have been successfully dealt with by the 

 instruments in the possession of not a few amateurs, so that 

 the devotion to them of the largest telescope and the most 

 gifted ob.server in the world is something to be regretted. But 

 since there was none other fulfilling the dutv, Mr. Burnham 

 has performed a great public service in discharging it, and 

 incidentally has succeeded in discovering some eighteen new 

 pairs, some of which are evidently of \'erv high interest. 



* « * 



Mr. Lowell on Changes in the Ma.rtian 

 Canals. 



Three papers reccntlj' published by Mr. Lowell carry his 

 researches on Mars a distinct stage fmiher. Two of these are 

 issued as Bulletins Nos. 7 and 8 of the Lowell Observatory, 

 and deal with the variation in colour of the Mare Erythasum 

 and the alternating appearances of the canals Thoth and 

 .\menthes. The third paper, entitled "The Cartouches of 

 Mars," was communicated to the .American Philosophical 

 Society. In this last Mr. Lowell discusses some 375 drawings 

 of the planet, made during the opposition of 1903 from 

 January 21 till July 26. Eighty-fivo canals were observed, and 

 each canal on the average might have been seen one hundred 

 times. For each canal a curve or " cartouche " was drawn 

 out to exhibit the percent.ige of times that it was observed 

 wlien, from the presentation of the planet, it should have been 

 visible, for different intervals after the sunmier solstice. The 

 mean cartouches for the different zones are far from being 

 convincing, and represent the smoothing out of many discord- 

 ances. It may be granted, however, that there is some slight 

 resulting evidence that on the whole the date of greatest dis- 

 tinctness for a canal falls later in the summer of Mars in pro- 

 portion to its distance from the pole. This darkening of the 

 canals proceeds towards the equator at a speed of 53 miles a 

 day. Mr. Lowell considers this as motion in the face of 

 gravity, the equatorial radius of Mars being eleven miles 

 greater th.in the polar, and as demonstrating that the canals 

 are waterways and that the water is raised to this height by 

 artificial means. The Thoth and the .■\menthes offer a case, 

 according to Mr. Lowell, of alternative canals, the one canal 

 being visible in one season and the other in another. Mr. 

 Lowell also finds that the Mare Erytha;um shows a distinct 

 bl';e-green tint at the time when he infers there is most moisture 

 in the region and a chocolate-brown when there is least, a 

 change he ascribes to the decav of vegetation. 



* * * 



Sunspots and Terrestrial Magnetism. 



Professor Ricco contributes ;in inijiortant memoir on this 

 subject to the Societa degli S])ettroscopi It.aliani. He refers 

 at length to Mr. Maunder's recent paper on the nineteen great 

 m.agnetic storms of the last thirty years, and fully adopts his 

 conclusion that there is a real connection between sun-spots 

 and such storms. Mr. Maunder found that the storms began on 



the average 26 hmii-. ilter the transit of a great spot across 

 the central meridian of the sun. Professor Ricc6 finds that 

 the maximum violence falls about 455 hours after the transit. 

 As the mean duration of a storm is a hours, the two deter- 

 minations are almost precisely in accord. Referring to a num- 

 ber of suggestions which have been made to explain the sun's 

 influence on terrestrial magnetism. Professor Ricco appears to 

 favour that of Arrhenius, who suggests ions, driven from the 

 solar surface by reason of the pressure of radiation : their 

 velocity being nearly tliat indicated by the interval mentioned 

 above. 



ZOOLOGICAL. 



Ea.rly Opening of the Bright Eye. 



In a note to certain observations on the gestation of the 

 badger, published in the March number of the Zoolof;ist, Mr. 

 A. Heneage Cocks records the following \ery remarkable cir- 

 cumstance : " I have never seen the fact noticed," he writes, 

 ■• that the right eye of young mammals opens before the lelt. 

 I do not remember an exception among wild animals, nor even 

 among domestic animals, though it is very likely some occur 

 in the latter class. From the time the lids of the right eye 

 begin to part to the time the left eye is fully opened takes 

 generally from 36 to 40 hours." The fact is as new to us as it 

 is to Mr. Cocks, and requires an explanation. The suggestion 

 naturally occurs that the phenomenon is coimected with 

 "right-handedness" in the human species; but before such an 

 explanation can be accepted, we want to know whether car- 

 nivorous and rodent mammals, and the membersof such other 

 groups as have the young blind at birth, display a similar 

 preference for using the right limb. The horse, it is well 

 known, di.splays a decided tendency to " lead with the left 

 foot ; " but in this species, in common with other ungulates, 

 the young are born with their eyes wide open. And what 

 holds good in this respect with domesticated horses may not 

 obtain among carnivores and rodents. 



The "Pearl Organs " of Fishes. 



Tiie males of certain species of North American fishes 

 develop during the breeding season what are known as " pearl- 

 organs." These are hard spine-like thickenings of the epi- 

 dermis, sometimes forming rows on the sides of the tail and 

 on the anal fin. Their use long remained unknown. Mr. J, 

 Reigh ud, of Michigan Universit}', finds, however, that they 

 are employed by the males of some species for fighting and in 

 building their nests, while in all the species they are used for 

 holding the spawning female. 



Whale Collisions. 



Two instances of the sudden destruction of whales by colli- 

 sion have recently been recorded in the daily papers. In the 

 one instance the look-out on a liner noticed a large whale dis- 

 porting himself OT the surface of the water immediately ahead, 

 but, thinking that the monster would get out of the way in 

 time, the vessel was allowed to pursue her course. Instead, 

 however, of moving, the whale .remained where he was, and 

 was caught " amidships " by the bows of the steamer, which 

 cut him conipletelv in two. For two or three miles, it is said, 

 the vessel ploughed her way through water crimsoned with 

 the leviathan's blood. The second case is recorded in a tele- 

 gram sent from Vladivostok on March 30. " A violent ex- 

 plosion," runs the message, " recently occurred at sea in 

 Possiet Bay, the cause of which could not be ascertained. 

 Two days later the bodj' of an enormous whale was washed 

 into the bay by the tide, the creature having evidently collided 

 with and exploded a mine." 



Monkeys aLnd Altitude. 



A recent issue of the ^//i of the Roval Academy of Rome 

 contains an account of the effects produced on baboons and 

 monkeys bv conveying them to a high elevation on Monte 

 Rosa. The ill effects seem more pronounced than in the case 



