2 86 



SCIENCE- GOSSIP. 



Pallas, for instance, has an inclination of 34 c- 7, 

 but, on the other hand, Massilia is only inclined 

 o- 7. There is also considerable difference in the 

 size and shape of the orbits, for whilst No. 330 is 

 comparatively near the orbit of Mars, No. 380, 

 shown, together with another newly-discovered 

 planet, on the photograph of November 4th, 1901. 

 is far out towards that of the planet Jupiter. All 

 planets travel in paths more or less elliptical, 

 Venus is most nearly circular amongst the major 

 planets, the amount of its eccentricity being ex- 

 pressed as - 0068. Among the minor planets the 

 eccentricity of Europa amounts to only 0'004, 

 whilst the object photographed at Arequipa on 

 August 14th, 1901, is one of the most eccentric 

 known, that element being expressed" as 0'377. 

 This means that when nearest the Sun its distance 

 is only 148,800,000 miles, but when farthest 

 329,220,000 miles separate the two bodies ; but 

 this eccentricity is exceeded by Aethra. The 

 nearest of the little planets has a year lasting, 

 in extent of time, to about three of ours, but 

 the most distant one occupies nearly nine years 

 in travelling its path. 



Professor Barnard's measures with the 36-inch 

 Lick telescope in 1894 gave the actual diameters 

 of Ceres, Pallas, and Vesta as 599, 273, and 237 

 miles respectively. The rest, excepting Juno, are 

 all much smaller ; it is doubtful if the greater 

 portion of them do not vary between 15 and 5 miles 

 in diameter, the figures given by Hornstein. 



As telescopic objects, at least with all but the 

 largest telescopes, they are a failure, appearing as 

 tiny stars varying in size from 6 "6 magnitude to 

 the tiniest points, some shining with a ruddy, 

 others with a bluish light. As objects on the 

 photographic plates, it will be seen, by the examples 

 here given, they are represented by thin lines of 

 varying angles. These are caused by the motion of 

 the planets among fixed stars during the exposure 

 of the plates, which occupied, as already noted, 

 two hours in both cases cited. The images from 

 the stars are kept motionless on a photographic 

 plate, by means of clockwork. 



Quite separate from the other minor planets is 

 Eros, having an orbit mostly within that of 

 Mars. It was discovered August 13th, 1898, 

 by Herr Witt, of Berlin, and is without doubt 

 the most important of the minor planets from 

 an astronomer's point of view. When nearest 

 to the Earth its distance is only about 13,000,000 

 miles, or little more than half .that of Venus when 

 in transit. Its distance from the Sun varies from 

 1T333 to T7828, taking the Earth's mean distance 

 as 1-0. The most favourable oppositions of the 

 planet during the near future will be in the years 

 1917 and 1924, when every effort will be made to 

 determine with more exactness the actual distance 

 of the Sun from the Earth, and also the relative 

 masses or weights of these two bodies. When 

 nearest to the Earth, Eros appears as a star of, say, 

 sixth or seventh magnitude, but it is usually much 

 smaller. The discovery of its variability within a 

 period of about 2h 22m. leads one to suppose from 

 the nature of the variation that the planet is closely 

 double, and that the components revolve in an 

 orbit whose plane at times passes through the 

 Earth. In the middle of February 1901 the varia- 

 tion was found to be from 9'3 to 11-0 magnitudes. 

 Its revolution round the Sun is accomplished in 

 (543T days. 



(To he continued.') 



Evolution of Pain and Pleasure. — I am 

 acquainted in a general way with the accepted 

 principles of organic evolution, but I cannot re- 

 member coming across any discussion of the 

 evolution of pleasure and pain in the works of 

 Darwin, Wallace, Eomanes, or Haeckel. There is 

 a popular belief that low forms of life are not 

 capable of much pleasure or pain. Can this view 

 be justified from the Darwinian standpoint ? Could 

 it be argued with any force that, other things being 

 equal, the animal that enjoys and suffers most is 

 the fittest animal, and that consequently pleasure 

 and pain are selected by nature in the same way 

 as fleetness, strength, cunning, or other attributes 

 of value to the existence of animals 1 Some 

 observations on house flies which I made during 

 the summer have led me to think that these crea- 

 tures do not suffer, in an analogous way to man. I 

 have found several times that a fly, immediately 

 after one of its legs is pulled off, will proceed to 

 devour sugar. I shall be very grateful if any of 

 your readers can give me information on this sub- 

 ject, or can refer me to authors who treat it in a 

 popular way. — William Smith, Glasgow. 



Animals and Telegraph-poles. — The note in 

 Science-Gossip, ante, p. 241, on the damage done 

 to telegraph-poles by woodpeckers reminds me that 

 at the Paris Electric Exhibition of 1881 specimens 

 of portions of telegraph-poles were exhibited to 

 show the damage done to them by woodpeckers, 

 and also by bears. The birds seemed generally to 

 attack the poles near the top, and in some cases 

 ■holes had been made large enough to pass the 

 hand through ; but the bears had gnawed away the 

 wood nearer the ground, thereby weakening the 

 poles to such an extent that they broke off and fell 

 under a very moderate wind pressure. It was 

 clear neither the birds nor the beasts wanted to 

 devour the wood, and it was explained that their 

 attention was drawn to the poles by the humming 

 noise produced by the vibrations of the wire, and 

 communicated to the poles by conduction. Whilst, 

 therefore, the woodpeckers endeavoured to get at 

 the insects which they imagined were living some- 

 where inside the pole, the bears, under the 

 impression that there must surely be a bees' nest 

 inside, had made strenuous efforts to secure the 

 honey, of which they are so passionat'elyifond. The 

 immunity of a majority of the poles, in contradis- 

 tinction to the attacks upon others, was thought to 

 be due to a fine sense of discrimination on the part 

 of the animals, which induced them to trouble only 

 about the poles that resounded with notes of pre- 

 cisely the same pitch as those naturally produced 

 by the particular insects desired. No doubt paint- 

 ing the poles would tend to preserve the wood from 

 the influences of the weather, but as this would 

 not stop the humming, it. is extremely doubtful if 

 it would be to any extent a remedy for the 

 mischief above mentioned. The cure seems rather 

 to lie in the direction of insulating the wires in 



