14: EEPOET OF THE SECEETAEY. 



" The representation of the observations by the concluded theory will 

 probably be regarded as good. The mean outstanding difference dur- 

 ing each five years since the discovery of the planet only exceeds a 

 second of arc in a single instance, namely, during the years 1822-'26, 

 when it amounts to 1".4. This agreement is very much better than any 

 obtained before. Still the vast number of observations used, and the 

 care taken to reduce them to a uniform standard, led me to believe a 

 better representation possible ; and the outstanding differences, minute 

 though they be, follow a regular law, thus showing that they do not 

 arise from the purely accidental errors of observation. How far they 

 arise from errors in uay own theoretical computations, how far from the 

 reductions of the observations themselves, and how far from the una- 

 voidable errors of the instruments, I am unable to say without further 

 investigation. It would be desirable to learn whether they may be due 

 to the action of a trans-Neptunian planet, but to do this would require 

 an entire re-reduction of all the older observations. Such a work is on 

 many accounts an astronomical desideratum, but it could not be under- 

 taken except under the auspices of the Government. 



" In the eighth chapter the general formulae and elements are collected 

 and expressed in the form most convenient for permanent use. 



"The ninth and concluding chapter gives tables by which the position 

 of the planet may be computed for any time between the Christian era 

 and the year 2300." 



It has been mentioned in several of the reports that the Institution 

 has collected large numbers of vocabularies of the several Indian lan- 

 guages of North America, including those of the Indian tribes of Wash- 

 ington Territory, California, northwest coast, New Mexico, Arizona, and 

 the prairies ; that these had been placed in the hands of Mr. George 

 Gibbs for critical study and revision ; and that, after consultation with 

 some of the principal philologists of the country, it had been concluded 

 to publish them, as it were provisionally, as material for ethnological and 

 linguistic investigations. During the past year Mr. Gibbs has devoted 

 considerable time to the arrangement of these vocabularies, and has 

 completed the preparation for the press of one of the sets, namely, that 

 of the Selish language, which is now in the hands of the printer.* 



In order to facilitate the re-arrangement of the collections of the 

 National Museum, the Institution has requested experts in the various 

 branches of zoology to prepare catalogues exhibiting the best arrange- 

 ments of the several classes of the animal kingdom ; the families, in 

 each case, to be numbered in successive order, and the subfamilies to 

 be indicated by letters, thus: "15, Canidaa; (15) a, Caninae; (15) &, Mega- 

 lotinaj," &c. It is intended that these numbers and letters shall be 



* Since the presentation of this report, the work in question has been stopped by the 

 death of Mr. Gibbs, one of the most esteemed collaborators of the Institution. 



