OF ARTS AND SCIENCES, 125 



were precisely adapted to the conduct of this national work, so impor- 

 tant to commerce and navigation, and so interesting to science. After 

 the lapse of five years from the date of his appointment, it is deemed 

 reasonable to comply with Professor Bache's request to make a careful 

 examination of his labors, and inquire if the high expectations which 

 had been formed have been realized ; if there has been so rich a 

 harvest of valuable results as might have been anticipated ; if the best 

 methods of observation have been uniformly adopted ; and if the sur- 

 vey has been conducted throughout with proper economy and despatch. 

 Your committee have made this examination to the best of their ability, 

 and have thought it advisable to present their conclusions in as simi)le 

 and condensed a form as possible. The tone of the report is necessarily 

 laudatory, for the committee are persuaded that the minutest and most 

 conscientious scrutiny will find every thing to approve and nothing to 

 condemn. 



" 1. The methods and instruments of observation appear to be, in 

 all cases, the most convenient and accurate which are known ; while, 

 in some striking instances, they are such as were not known or tried 

 in geodetical operations before they were introduced upon this survey. 

 It is, moreover, grateful to record, that some of the most important 

 of these improvements are of American origin. The committee beg 

 leave to refer to some examples. 



" The apparatus for measuring the base-lines is so portable, that six 

 and three fourths miles are measured in ten working-days, and so ac- 

 curate, that the whole amount of possible error in this distance would 

 not exceed half an inch. This beautiful apparatus, which is incom- 

 parably superior to any which has ever before been adopted, is in 

 principle and combination the invention of the Superintendent himself. 

 It is a compensating system, and is in this respect closely allied to the 

 elegant arrangement invented and used by Mr. Borden in the survey 

 of the State of Massachusetts, but the method of compensation is novel 

 and original in an essential and characteristic feature. 



" The method which has been finally adopted for the measurement, 

 astronomically, of differences of latitude is that which was invented by 

 Captain Talcott, late of the Corps of Engineers of our army, and 

 which had not before been used for geodetical purposes. A full de- 

 scription of this method has been recently published in an unusually 

 handsome form by the Topographical Bureau of the War Department, 

 in a memoir written by Captain T. J. Lee, which contains some exam- 



