150 EIGHTH ANNUAL REPORT OF 



kind. Bat this is obviously impossible, for they alone would exhaust all 

 the income of the Institution. 



Preparations have been made for the publication of the second volume 

 of the Contributions, and a sufficient number of memoirs have been 

 already accepted, or are in preparation, to furnish the materials. Five 

 of these are on astronomical subjects, and afford as important additions 

 to this science as have ever been made to it in this country. Two of 

 them relate to investigations on the new planet Neptune, which are 

 only second in value to the original discovery of this distant member of 

 our system. Abstracts of these have been given to the world, and have 

 been received with general approbation. A third is a determination of 

 the zodiac of the asteroids, or the zone in the heavens to which the 

 positions of these small planets are confined. This paper is of much 

 practical importance in facilitating the researches now in progress in 

 different parts of the world relative to the nature of these fragments (as 

 they would seem to be) of a large planet between Jupiter and Mars. 

 It may be at once determined, by an inspection of the table annexed 

 to this paper, whether any star mapped in an old catalogue, and now 

 no longer to be found in the same place, can possibly be one of the 

 asteroids. A fourth paper is an account of a new comet, the discovery 

 of which by an American lady is one of the first additions to science of 

 this kind, so far as I am informed, ever made in this country. The fifth 

 memoir is an account of the Georgetown Observatory, the instruments 

 with which it is furnished, the mode of using them which has been 

 adopted, and the results of the observations which have been made. 

 An important paper is also in process of preparation for the same 

 volume on the gigantic fossil cetacean remains which are found in the 

 southern and western States of the Union. 



Other papers are in progress which partake of the character of origi- 

 nal researches, since they are, in part, at least, prepared at the expense 

 and under the direction of the Smithsonian Institution. They will be 

 mentioned under the next head. 



In a few cases, memoirs have been presented which, though exhi- 

 biting research and considerable originality, are not of a character to 

 warrant their adoption as parts of our volumes of Contributions to posi- 

 tive knowledge. The rule given in the programme has been rigidly 

 adhered to, viz: to decline accepting any paper on physical science 

 which consists merely of an unverified hypothesis, however ingenious 

 and plausible such an hypothesis may be. A law of nature is not sus- 

 ceptible of a logical demonstration, like that of a proposition of geo- 

 metry, but is proved by its fitness to explain old, and to predict new, 

 phenomena. The verification of an hypothesis, as we have stated in 

 the last report, consists in deducing consequences from it, and ascer- 

 taining, by a direct appeal to observation or experiment, the truth 

 or falsity of these deductions. Any paper, therefore, on material 

 science, which does not contain original experiments and observations, 

 cannot be admitted as a part of the Contributions to Knowledge. The 

 rule we have adopted is in accordance with the practice of cautious 

 investigators. The law of universal gravitation existed for several 

 years in the mind of Newton as a well conditioned hypothesis before 

 it w 7 as given to the world as a verified and established theory. Besides 



