NOVEMBEB 5, 190!)] 



SCIENCE 



641 



sometime dismemberment of tlus orb, from wliich 

 disintegration our sun and planets were formed, 

 the little solitary bits of rock thus mutely witness. 



In the Atlantic Monthly for August, 1909, 

 in an article entitled " The Revelation of 

 Evolution," on page 177, after commenting on 

 and dismissing the Laplacian theory, he says, 

 in introducing more recent work : 



Without attempting here a picture of what 

 probably took place, let me sketch a line or two 

 of its reconstruction as they have taken shape 

 at midnight to one watcher of the stars. 



And on the following page we read : 



From the information afforded us by meteorites 

 we turn to another discovery of recent date, the 

 recognition of the spiral nebulae. . . . Xow, this 

 spectrum [that of the spiral nebulte] is just what 

 they should show were they flocks of meteorites — 

 and such they undoubtedly are. They give us, 

 therefore, the second chapter of the evolutionary 

 history. For, from their peculiar structure, we 

 can infer what the process was that scattered the 

 constituents of the once compact ball whose exist- 

 ence the meteorites attest. They consist of a 

 central core from which two spiral coils unfold, 

 the starting point of the one diametrically op- 

 posite the other. Now this is what would happen 

 had the original mass been tidally disrupted by a 

 passing tramp. Tides in its body would be raised 

 toward and opposite the stranger, and these would 

 scatter its parts outward; the motion due the 

 tramp combining with the body's spin to produce 

 the spiral coils we see. Just as in the meteorites 

 we have found the substances from which our 

 solar system rose, so in these nebulae we see an 

 evolution actually in process which may have been 

 our own. 



To those who have read the literature of the 

 planetesimal hypothesis as it has come forth, 

 stage by stage, during the past decade this will 

 sound strangely familiar; and when reading 

 Dr. Lowell's statements about the origin of 

 meteorites, one can not help but recall Pro- 

 fessor Chamberlin's article in the Astrophys- 

 ical Journal eight years ago, " On the Possible 

 Function of Disruptive Approach in the For- 

 mation of Meteorites, Comets and Xebulic." 

 But perhaps Dr. Lowell does not read the 

 Asfrophysical Journal, which is edited and 

 published not far from the home of that 



" geologist out West '" who '' astronomically 

 ... is unaware that what prompted his 

 contention, the Planetesimal Hypothesis, is 

 mathematically unsound." The Carnegie In- 

 stitution, however, is not so far "out West" 

 that it has forfeited its claim to " be treated 

 with respect," and in its " Year Books " of 1902 

 to 1907 are full expositions covering every 

 essential element that enters into the mid- 

 night reconstruction. 



From these quotations it is clear that Dr. 

 Lowell has a real aifection for the main fea- 

 tures of the planetesimal hypothesis, and if I 

 had not been so unfortunate as to have utterly 

 destroyed it (according to the new- logic) by 

 the blunder in my book 83 pages before I took 

 the hypothesis up, he might almost have re- 

 constructed it from his own recent writings. 

 I am wondering whether in his forthcoming 

 book on " The Evolution of Worlds "" he will 

 not give additional proof of his affection for 

 the planetesimal theory, though perhaps under 

 some other name, or in some nameless form, 

 more congenial to that mysterious " watcher 

 of the stars " whose scientific theories, like 

 Poe's visions of the raven, " have taken shape 

 at midnight." 



F. E. MouLTox 



'Atlantic Monthly, August, 1909, p. 181, foot- 

 note : " Even as this essay stood betw-een pen and 

 print a geologist out west, in a long letter to 

 Science, has repeated, in reference to the facts 

 here set forth, the old attacks on Darwin for 

 daring to synthesize the facts; though the geologic 

 facts are from Sir Archibald Geikie, our own 

 Dana and DeLapparent, who should certainly geo- 

 logically be treated with respect. Astronomically 

 he is unaware that what prompted his contention, 

 the Planetesimal Hypothesis, is mathematically 

 unsound." 



- In the advance description of this book we 

 read: "So important scientifically is the work of 

 Professor Percival Lowell that the announcement 

 of a new book by him might seem to belong rather 

 in the list of technical works than in a catalogue 

 of general reading. Professor Lowell, however, 

 has the rare art of conveying important and new 

 truths in language readily intelligible to the gen- 

 eral reader. . . . His theme is the process by 

 which a world comes into existence, the phases 

 through which it passes. . . ," 



