2G2 ANNUAL RECORD OF SCIENCE AND INDUSTRY. 



used. He lias furnished the instruments made by him with 

 three micrometer microscopes for reading the divisions of 

 the circle. The telescopes were provided with Kellner's 

 oculars, and the axis constructed of hard aluminium bronze. 

 The instruments were intended to be used for astronomical 

 as well as geodetic purposes. Borda's principle of repetition 

 was not introduced. The divisions of the circle were cut 

 by an instrument which is his own property, and itself con- 

 structed by him. This circle-dividing machine has a diam- 

 eter of over two feet. It does the dividing, and at the same 

 time corrects its own errors, and is therefore a self-acting 

 and self-correcting dividing-engine. It is evident that this 

 dividing-machine will be of great importance to German in- 

 strument-makers, from the fact that the dividing- machine 

 constructed for the state, at the instance of Alexander von 

 Humboldt, in the reign of Frederick William IV., and which 

 was officially delivered in 1867, seems to have disappeared; 

 at least no information can be obtained concerning it. 

 CarVs Hepertorium, X., 50. 



EXPLORATIONS OF PROFESSOR POWELL I1ST 1874. 



During the past season the field force under Professor 

 Powell, who has had charge of the Second Division of the 

 Geological and Geographical Survey of the Territories, has 

 been divided into two parties. The larger, under Professor 

 Thompson, has been at work in Middle and Southeastern 

 Utah along the Sevier River and the country to the east, 

 nearly to the Colorado. The other party, with Professor 

 Powell, has been carrying forward the work in a region of 

 country west of the Sanpete River in Northeastern Utah. 



The geographical survey has been extended by the ex- 

 pansion of a system of triangles from a base-line previously 

 established at Gunnison, making this the base of topographic 

 work. For hypsometric purposes Green River City, on the 

 Union Pacific Railroad, Salt Lake City, Gunnison, and Pang- 

 witch have been used as stations for base barometers; the 

 altitude of these points had been previously determined by 

 railroad surveys. The assistants in the topographic work 

 were Professor H. C. De Motte, of the Illinois Western Uni- 

 versity, and Messrs. Renshaw, Graves, Forbes, and Wheeler. 

 These gentlemen, with the exception of the last two, had 



