458 



SCIENCE. 



[Vol. I., No. 16. 



The fact being as stated, the question is, What is the 

 tribe of robins going to do about it?' It is idle to 

 suppose that tlie whole race of robins will continue 

 for long to ' get left ' in tliis way, or that they will 

 accept the sparrow's system of pillage as a finality, 

 to be submitted to as a part of the fundamental plan 

 of life in this best possible of worlds; and it will be 

 of interest for future observers to notice In just what 

 manner the conflicting interests of the two birds 

 shall, in the fulness of time, have been composed. 

 At least four lines of conduct would seem to be open 

 to the robin: he might thwack the offending spar- 

 row at the moment of his wrong-doing, or, indeed, 

 all sparrows, both as a preliminary to the hunting of 

 worms and on all convenient occasions, though these 

 operations would doubtless be somewhat laborious; 

 possibly he might learn to swallow the worm iii- 

 stanter, or perhaps even to fly away with it quickly 

 enough to elude pursuit; or he may, in despair, 

 ■wholly give up the pulling of worms. So far as 

 my own observation goes, though it must be said 

 that it has been confined to no great number of 

 individual robins, it would seem as if no inkling of 

 either of these plans has yet occurred to the suifer- 

 Ing bird. In so far as I have myself seen, each 

 particular robin, when, thus defrauded, looks and 

 behaves as if he did not clearly comprehend what 

 had become of his worm; and he speedily goes in 

 search of another, as if, on reflection, he had con- 

 cluded that he must have himself swallowed the 

 first. Meanwhile, a number of the sparrows who 

 had flown off in chase of the first robber with intent 

 to share his booty have returned, and are hanging 

 around the robin in readiness for his second stroke. 

 The probabilities that the robins will eventually find 

 out some way of circumventing the thieving spar- 

 rows seem stronger when we reflect that it is prob- 

 ably only a very short time, comparatively speaking, 

 since the robins began to pull earth-worms, anyway, 

 and consider how thoroughly well they now do this 

 work. To all appearances, a parcel of scattered robins 

 hopping about in a pasture are attending to any thing 

 but business. It is hard to believe, at first sight, 

 that the birds are seriously searching for fond; for 

 each one of them is continually stopping and stand- 

 ing still in an apparently aimless way, as if dis- 

 tracted. In point of fact, the bird, when quiet, is 

 intently watching for earth-worms in their burrows; 

 and it is more than probable that he is not helped at 

 this stage of proceedings by a group of sparrows 

 hanging expectant about him. When the worm, or 

 the place where the worm is, is perceived, the move- 

 ments of the robin are sufliciently direct and forcible, 

 as has just been stated. Inasmuch as there is good 

 reason to believe that earth-worms were not to be 

 found at all in this New-England country before its 

 settlement, and that, even if they did exist, they 

 were rare, it would seem that the robins must have 

 learned (he trick of capturing them within the last 

 two hundred or two hundred and fifty years. Even 

 if it be supposed that the earlier mbins may have 

 practised somewhat analogous movements with re- 

 gard to certain kinds of insects or their larvae, it will 

 still be reasonable to suppose that the first lesson, 

 how to detect and pull the worm, must have been in- 

 trinsically harder than the one now before the robins 

 of the period; viz., how to keep and hold the worm in 

 spite of the pygmy sparrow. F. H. Stobek. 



Intelligence of the cro-w. 



In Science, No. 1.3, is a letter with this title, which 

 I read with much interest, for the story is a very 

 pretty one, and it is too bad to disturb it ; yet I can 



but think the writer mistaken in the bird, for he 

 says, 'It seems that we had been strolling loo near 

 their nests in the walls.' Now, it is well known 

 that crows do not build in walls or cliffs; and none 

 of the crows which I have ever kept in confinement 

 ever used their claws with which to carry either food 

 or other materials. I kept a raven for several years, 

 which had its liberty, but always came for food when 

 called. I never saw it carry food or any thing else in 

 its claws. I have known it to carry off its own 

 rations, rob both dog and cat of theirs, making at 

 leaf:t three pieces, all of which it carried away in its 

 beak at once, never in its claws. During the stmi- 

 mer of 1882 I was living near high wooded cliffs, 

 on one of which this raven built a perfect nest. It 

 seems to me your correspondent must be mistaken. 

 Doi-chceter, Mass. JoS. M. WaDE. 



Sun's radiation and geologic climate. 



In saying that the hypothesis of a diminution 

 of solar radiation through the dissipation of solar 

 energy would be admitted by 'most students,' I did 

 not intend to include myself, for I am really a dissen- 

 ter. In my judgment, the weight of the cumulative 

 geologic evidence for the great age of the earth is not 

 counterpoised by the arguments thus far adduced 

 from the physical side of the question. I therefore 

 welcome Mr. Warring's note (Science, No. 14) in 

 that it helps to show that the physical conditions in- 

 volved in the discussion are not so simple as some 

 have assumed them to be. Perhajjs we may go a step 

 farther, and say, that even if it is demonstrated that 

 solar energy is being dissipated, and if it is demon- 

 strated that in consequence of this dissipation the 

 temperature of the sun is either falling or rising, the 

 relative intensity of solar radiation still remains an 

 unsolved problem. The rate of radiation is a func- 

 tion of other conditions besides temperature, and 

 notably iif the nature of the outer envelope of the sun. 

 It is quite conceivable that changes in the envelope, 

 belonging to the chemical history of the sun, might 

 materially modify any law of variation based upon a 

 theory of progressive dissipation of energy. This sug- 

 gestion is, of course, without experimental basis; but 

 in this respect it does not stand alone. Our labora- 

 tories fall so far short of realizing solar conditions, 

 that solar physics and solar chemistry cannot be con- 

 ceived without the aid of the imagination. ' 



G. K.Gilbert. 



Marking geodetic stations. 



Of the many hundred C<iast-survey stations that 

 have been marked at different dates within the 

 limits of the state of New York, only a very small 

 percentage have now, or ever have had, surface- 

 marks of any descriptiim, and but few of the under- 

 ground marks can be recovered without re-measuring 

 angles of the triangulali<m. 



I'lie manner of marking stations is apparently left 

 to the ju<lgment of the Coast-survey assistants. The 

 writer of the manual 'On the fleld-work of triangu- 

 lation,' issued by the Coast-survey, neglected to 

 place surface-marks at several of the" primary trlan- 

 giilation points occupied by himself in the vicinity 

 of Albatiy. 



A substantial surface-mark has been placed at 

 every geodetic station of the New York state survey; 

 and although some have been mutilated, so far as 

 is known, none have been removed. The number of 

 granite surface-marks that have been placed by the 

 survey is at preseut three hundred and twenty-nine. 



Horace Andrews, Jim., 

 Albany, May 12, 1883. Assistant N. Y. state survey. 



