THE SMITHSONIAN INSTITUTION. 169 



been received with much commendation. All the societies from which 

 we have as yet heard, have declared their willingness to co-operate 

 with the Institution, and to give us their publications in exchange, from 

 which source our library has already been enriched with valuable 

 additions. 



It is to be regretted that our means would not permit us to distribute 

 the first volume more liberally thnn we have done, and that the price put 

 upon the copies offered for sale has placed them beyond the reach of 

 many persons desirous of obtaining them. This arose from the fact, that 

 in order to remunerate the authors for the expense and labor bestowed 

 on the memoir, they were allowed to strike off from the types and plates 

 of the Institution an edition to be sold for their own benefit. To avoid 

 risk of loss, the edition was a small one, and the price put at ten dollars. 

 An occurrence of this kind will not happen again; for, although it would 

 be desirable to pay authors for then* contributions, yet it is now found 

 that materials will be offered, free of all cost, more than sufficient to 

 exhaust the portion of the income which can be devoted to publications. 



In printing the future volumes it will be advisable to strike oft" an 

 extra number of copies for sale on account of the Institution, and to dis- 

 pose of those for little more than the mere cost of press-work and 

 paper. 



The second volume of Contributions is now in the press, and will con- 

 sist of a number of memoirs which have been submitted to competent 

 judges and found worthy of a place in the Smithsonian publications. In 

 tJiis volume vve have adopted the plan of printing each memoir with a 

 separate title and paging. The object of this is to enable us to distri- 

 bute extra copies of each memoir separately, and also to furnish the 

 author with a number of copies regularly paged for his own use. It 

 will likewise enable us to classify the memoirs according to subjects. 



The following is a brief account of the memoirs contained in the 

 second volume, so far as they have been reported on by tlie commis- 

 sioners to whom they have been submitted : 



1. A memoir on the ijlanet Neptime, bij Sea7's C. Walker. — An abstract 

 of this memoir has been published in the proceedings of the American 

 Philosophical Society, and has received the approbation of the scientific 

 world. It presents the several steps of the discovery of an orbit which 

 has enabled Mr. Walker to compute the place of the new planet with 

 as much precision as that of any of the planets which have been known 

 from the earliest times.* Starting from the observations of the motion 

 Off the planet during a period of about four months, Mr. Walker calcu- 

 lated an empirical orbit, which enabled him to trace its path among the 

 stars of the celestial vault through its whole revolution of 166 3'ears. He 

 was thus enabled to carry its position backward until it fell among a clus- 

 ter of stars accurately mapped by Lalande towards the close of the last 

 century; and, after a minute and critical investigation, he was led to 

 conclude that one of the stars observed by Lalande on the night of May 



*It is proper to state that a part of the researches given in this memoir was made during 

 the author's connexion with the National Observatory, under the direction of Lieutehant 

 Maury. An account of these will probably soon be published in the next volume of the 

 records of operations of this observatory. 



