94 



SCIENCE. 



[Vol. IV., Xo. 78. 



where engaged on the same humane service. 

 Greely and his associates took their lives in 

 their hands for the good of humanity, as 

 the soldier does when he enters the army, 

 as the physician when he studies the scourge, 

 as the missionary when he penetrates the dark 

 continent, as the navigator when he enters un- 

 known seas. Some of the number have fallen 

 without reaping the rewards of their enterprise ; 

 some are returning with emaciated forms ; all 

 bravely did their part, and will be honored by 

 their countiymen. 'Peace has its victories as 

 well as war ; ' and those who have fought frost 

 and famine, who have endured the hardships 

 of three polar winters, that they might add to 

 huirran knowledge, deserve the lasting grati- 

 tude of all thoughtful men. In days when 

 luxury and comfort chain so man} T people to 

 the fireside, and when the occasions for heroic 

 action are so rare, it is good for human nature 

 to witness fresh examples of heroism, all the 

 better that these examples are for the sake of 

 advancing science. All honor, therefore, to 

 Greely and his brave companions, living and 

 dead ; and honor, too, to Schley and his crew 

 for the rescue they effected with so much skill. 

 Now that these men have reached the ports of 

 their native land, there should be a better wel- 

 come for them than disparaging remarks, and 

 the hope that there will be no more such efforts. 

 ' Let knowledge grow from more to more,' and 

 let those who extend its boundaries b}' hard- 

 ships and bravery have their honorable places 

 in the annals of science, and be welcomed 

 without reserve when their arduous exploits 

 are concluded. 



As the season approaches when our scien- 

 tific men congregate for consultation upon 

 matters of common interest, it may be well to 

 call their attention to a small matter, which is 

 really of more consequence than would at first 

 appear ; namely, to the practice of repaging 

 authors' extra copies of articles published in 

 journals and transactions of learned societies. 

 The practice here complained of must occa- 

 sionally be annoying to physicists, and, indeed, 

 to every one who wishes to cite correctly, or 



to look up the references of previous writers ; 

 but it is severely felt by naturalists, who have 

 so mam- names to cite or refer to, and to whom 

 correct bibliography, and prompt and right 

 reference, are essential. In the case of an 

 actual reprint in an independent form, there 

 may be good reason or necessity for repaging ; 

 yet even then the original pagination should 

 be indicated. But in printing extra copies 

 from the original type, there is no such neces- 

 sity, and no real advantage : on the contrary, 

 much disadvantage and confusion arises when 

 a paper is cited from the journal or transac- 

 tions of a society to which it was contributed, 

 but under wrong pages. Some societies and 

 journals refuse to have the original pagination 

 removed ; and, in our opinion, all should do 

 so. Separate paging in addition may be per- 

 mitted ; but it were better to dispense even 

 with this. 



LETTERS TO THE EDITOR. 



*** Correspondents are requested to be as brief as possible. 

 The writer's name is in allcases required as proof of good faith. 



Light in the deep sea. 



Professor Verrill's article in Science, No. 74, sug- 

 gests the inquiry whether the faint light that he 

 supposes to penetrate the deep seas may not have 

 some rays of nearly all colors, and appear greenish 

 to the deep-sea dwellers merely from an excess of rays 

 of more rapid vibration, just as the sky appears blue 

 from an excess of blue rays, not from the absence of 

 other colors; and, further, whether the light reflected 

 from the bright red or orange-colored animals that 

 have been dredged from great depths does not give a 

 many-colored spectrum, as is often the case with 

 colored objects, so that, even when illuminated by 

 greenish light, such animals would not necessarily be 

 dull or black or invisible, but might be distinctly 

 colored. If these questions were answered affirma- 

 tively, the explanation of the colors of deep-sea 

 creatures by the operation of protective imitation 

 would not be simple. W. M. Davis. 



Cambridge, July 12. 



The long-continued ' bad seeing.' 



' A fellow of the Royal astronomical society,' in the 

 English mechanic and world of science, vol. xxxix. 

 p. 345, writes, — 



"... As to the bad definition incident on the visibility of the 

 afterglow, I should like to remark, that, for some time past, day- 

 light definition of celestial objects has been worse than ever I 

 remember it during my tolerably long observing experience. 

 Transit-taking in daylight, save with the larger stars, has been 

 quite impracticable, and over and over again I have looked in 

 vain for Mercury. Of course, every one who is in the habit of 

 using a telescope in the daytime is familiar with the fact, that on 

 many seemingly cloudless days there is an otherwise invisible 

 kind of haze, which impairs or destroys definition, and that the 

 best or brightest vision is obtained in the blue sky visible be- 

 tween large, floating annuli; but this curious obscuration has 



