APPENDIX TO REPORT OF THE SECRETARY. 89 



gon, all of which area was occupied with a view to correct topographical 

 data, and the triangulation carried as far north as Beatty's Butte. 



Returning by the east shore of Goose Lake, Granite Mountain, and 

 Honey Lake, to Verdi, Nev., a base line was measured and the triangu- 

 lation of 1876 and 1877 connected. The country surveyed by this party 

 embraced i^arts of California, Oregon, and Nevada, and is of volcanic 

 origin. Water is scarce, and except in the valleys there is scanty veg- 

 etation. 



The party under Lieutenant Macomb pursued its labors principally in 

 the area of atlas-sheets 47 D and 5G B; its route was up Carson Valley 

 and canon into Hope Valley to Placerville, Cal. ; thence north and 

 among the headwaters of the American and Yuba rivers, connecting 

 with work of the previous year. In August it again moved from Placer- 

 ville eastward across the Sierras, occupying numerous triangulation 

 points, to Silver City. Thence it moved south to Sonora Pass, and as 

 far as Bridgeport, Cal. From thence its course was north by the Sweet- 

 water Mountains, and west by San Andreas, to Silver City, for sup- 

 plies, at which point the geologist was occupied for nearly a month in 

 the mountains east of Carson Valley, and the field-season closed. The 

 following summary shows a number of the principal instrumental 

 observations made: 



Number of azimuths measured, 13; number of sextant latitude sta- 

 tions occupied, 118; number of main triangulation stations occupied, 

 108; number of secondary triangulation points occupied, 202; number of 

 three-point stations occupied, 1,414 ; number of meander stations occu- 

 pied, 11,227; number of variations of the needle taken, 423; number of 

 miles measured, 9,728; number of cistern-barometer stations occupied, 

 1,255; number of aneroid stations occupied, 7,558. The highest alti- 

 tude noted was 14,415 feet, and the lowest 900 feet, the latter at San 

 Andreas, Cal. 



The special parties operating in Utah, Idaho, and Nevada, other than 

 Lieutenant Wheeler's, consisted of Dr. Kampf, Miles Rock, and Francis 

 Klett, and their assistants. The results of their labors consist in the 

 establishment of a number of main triangulation stations, the measure- 

 ment of three bases, the occupation of a number of trigonometric stations 

 in the valley of the Great Salt Lake about Ogden, and the measurement 

 of several minor traveled routes from the Union Pacific Railroad to the 

 northward. The special parties in the California section were occupied, 

 one, under Mr. Weyss, in the Lake Tahoe region, productive of very 

 interesting topographical results; and one, consistingof John A. Church, 

 mining engineer, and A. Karl, in a critical survey of the Comstock 

 Mines, an interesting preliminary report of which has been made 

 by Mr. Church. The examination of the Washoe mining region, in 

 which the famous Comstock lode is situated, consists of an elaborate 

 contour survey of the entire area covered by the mining and milling 

 works, delineated upon a scale of one inch to five hundred feet, each 



