July 9, 1886.] 



SCIEjSCE. 



35 



less important factor than wind-friction. Those 

 interested in the subject will do well to read the 

 chapters on ocean- currents in Croll's ' Climate and 

 time,' and the papers by Croll and Carpenter in the 

 London and Edinburgh Philosophical journal, and 

 the Proceedings of the Eoyal society. 



J. S. Newberry. 

 Columbia college, July 1. 



Private research and government science. 



Since the promulgation and discussion of the bill to 

 curtail the work of the scientific bureaus at Wash- 

 ington, and Mr. Herbert's appeal "to the best liter- 

 ary and scientific thought of the country to come to 

 our aid and join us in the effort to effect a reform and 

 arrest this pernicious tendency," much has been writ- 

 ten and said upon this subject. 



One of the chief arguments brought to bear by 

 those opposed to the extraordinary scientific progress 

 being made, and the vast amount of scientific work 

 being done by this country at the seat of its govern- 

 ment, is, that this work is proving detrimental to pri- 

 vate research in similar channels. 



Further, it has been said by the opposition that these 

 scientific publications of the U. S. geological survey 

 are valueless in the book-markets of the world ; and 

 Mr. Herbert points to that law in the organization of 

 the survey which specifies that it shall sell all its pub- 

 lications not exchanged at cost, and that during the 

 past six years this sale has realized an amount but 

 slightly exceeding fifteen hundred dollars. 



Now, one of the best proofs that this scientific 

 activity on the part of the government is in no way 

 checking private research, has been recently brought 

 forward by Professor Agassiz. who laid before this 

 commission of investigation the titles of forty- eight 

 publications of the Museum of comparative zoology 

 at Cambridge, alone. 



But perhaps a still better light is thrown upon these 

 two latter questions by an unprejudiced examination 

 of such a catalogue as is published by Dulan & Co. of 

 37 Soho Square, London. Here we find five of Mr. 

 0. G. Elliot's zoological monographs on sale for five 

 hundred and forty-five dollars, and other evidences 

 of the very highest activity in private research in 

 America on every page. Moreover, to prove that the 

 government publications of this country are not held 

 as being valueless in the book markets of the world, 

 we see any number of the publications of the geologi- 

 cal survey, and other scientific bureaus of Washing- 

 ton, on sale in the above catalogue, and being sold at 

 prices fully equalling those of private pulications. 

 That more money has not been realized at the survey 

 for the sale of its works, simply speaks in favor of 

 how eagerly they are sought in exchange, leaving but 

 a few copies each year on hand for sale. 



The excellent handbooks of geology of this country 

 by Dana and LeConte do not seem to have been sup- 

 pressed by government interest in this highly impor- 

 tant work ; and if we run our eyes over the bibliog- 

 raphy and illustrations of this science, as set forth 

 in these two volumes, I defy any one to say that the 

 government work is not appreciated, or that private 

 researches in this field are checked. The same holds 

 good for all the other sciences. 



I think when the sense of the vote of the " best 

 literary and scientific thought of this country " is 

 taken upon Mr. Herbert's appeal to suppress such 

 works as the paleontological monographs of Marsh, 



Ward, White, and others, and the magnificent pub- 

 lications in the bibliography of science undertaken 

 and accurately carried through by our government 

 there will be an enormous zero on his side of the 

 ticket. Government moneys can be squandered on 

 far worse things in the times of peace, than such 

 schemes as powerfully aid the progress of knowledge, 

 culture, science, and learning. Be it said to the 

 credit of this country that she sees fit to invest her 

 surplus means to the advancement of such ends. 



R. W. Shufeldt. 

 Fort Wlngate, N. Mex., June 29. 



Expulsion theory of comets. 



Mr. Proctor's article in a recent number of the 

 Nineteenth century, on the expulsion theory of 

 comets, leads one to believe that the solution of this 

 problem is not only as far off as ever, but that little 

 headway is being made for a general clearing-up of 

 the ' mystery.' There are many serious objections to 

 this particular theory of the origin of comets. We 

 admit, of course, that the earth and Mars, for instance, 

 or even the moon, may have been at one time scenes 

 of vast fiery eruptions, etc. But that this cast-off 

 matter should go out into space in a burning state. 

 and continue to go out, probably, for a great number 

 of years, then return, still in a burning state (the 

 alleged comet), — while the body from which it was ex- 

 pelled, and a much greater size as a matter of course, 

 always remaining in close proximity to the sun, and 

 drawing closer all the time, should cool down and be- 

 come solid and non-luminous, such as the earth. Mars, 

 or the moon is at the present time, — is certainly some- 

 thing on which Mr. Proctor's theory throws Httle 

 light. The expelled matter must naturally cool down 

 the same as the body from which it was expelled, and 

 except by accident, considering the distance it would 

 have to travel to meet another source of heat (a sun), 

 we can only come to one conclusion in regard to the 

 expulsion theory, it won't do. G. 



Brooklyn, June 39. 



Flooding the Sahara. 



Mr. G. W. Plympton's very interesting and sugges- 

 tive article on the flooding of .the Sahara {Science, 

 vol. vii. pp. 542-544) induced me to make some 

 numerical estimates, based upon the data furnished 

 by him, which may be of some interest to readers of 

 Science. He shows that " the area, which, lying be- 

 low the Meditenanean, can possibly be flooded by it " 

 (the united areas of the depressed portions), is, by M. 

 Roudaire's measurements, about 3.100 square miles ;, 

 and the average depth, if flooded, would be 78 feet. 

 Now, assuming the area of the cross-section of the 

 water of the Inlet Canal to be 2,000 square feet, and 

 the average velocity of the inflowing water during 

 the whole time of flooding to be 2 feet per second (not 

 a low estimate), it follows that the average inflow 

 would be 4,000 cubic feet per second = 3,456 X 10" cubic 

 feet per day = 1,262,277X10" cubic feet per year. 



Again: 3,100 square miles = 864,230x10* square 

 feet ; and, the average depth being 78 feet, the 

 amount of water required to flood it to this depth 

 = 67,409,971x10* cubic feet. Consequently such a 

 canal would require 53.4 years to flood the compara- 

 tively small and shallow Saharian lake, under the 

 assumption that duiing the inflow no water was lost 

 by evaporation or by absorption into the porous bed.. 



