90 APPENDIX TO REPOKT OF THE SECRETARY. 



contour represeuting a vertical distauce of fifty feet. The field-work for 

 this purpose is uow completed. Cross-sectious at horizontal distances 

 of one hundred feet are being made; the workings along each of the 

 opened levels of the numerous mines are being mapped, and a longi- 

 tudinal section on an aijpropriate scale will show most accurately the 

 relative i)osition of the mines, their present openings, and the lines of 

 all tunnels, including the Sutro Tunnel. In this work the engineers 

 and surveyors of the region have gratuitously contributed the use of 

 their maps and tracings made by them for the several mining companies, 

 and especially Mr. I. E. James, whose name in this relation has been 

 connected with the Oomstock Mines almost continuously since their 

 early working. The examinations proposed to be made include the sub- 

 ject of temperatures, ventilation, drainage, and treatment of ores. In 

 this work, that must cover a number of years in order to prove success- 

 ful, the officer in charge will be able to devote some of his time, and the 

 different problems involved will be submitted to experts in the branches 

 of geology, mineralogy, and metallurgy. 



Mr. Henshaw, zoological assistant, accompanied party Ko. 1 of the 

 California section as far as Southern Oregon, and largely supplemented 

 the collections made during the j)revious year illustrative of the zoology 

 of that interesting region. The habits of the water-birds were carefully 

 studied, and large collections made of skins and eggs. A thorough col- 

 lection of fishes was also made, and the discovery of a large and tine 

 trout, one of two species inhabiting Lake Tahoe, is announced. The 

 Lepidoptcra, Orthoptera, &c., gathered have yet to be examined and re- 

 ported upon. 



Mr. A. K. Conkling accompanied party No. 2 as geological assistant, 

 and examined the eastern and western slopes of the Sierras, in contin- 

 uation of previous examinations. Some important mining stations were 

 visited, including Bodie, where new and promising discoveries of gold- 

 bearing quartz have been recently found, and Aurora, which is again 

 becoming prominent. The country examined, however, offers few 

 problems of interest to the geologist, presenting a monotonous uniform- 

 ity of structure, granitic rocks largely predominating, with occasional 

 evidences of volcanic outbursts. Volcanic breccia abounds in some 

 sections. Evidences of glacial action, so abundant at Lake Tahoe, were 

 found at various points southward, notably about the headwaters of 

 the Stanislaus, American, and Mokelumne rivers. A small collection 

 of vertebrate fossils of the Tertiary age was made near Carson, Xev. 



At the Washington office the usual number of draughtsman have 

 been continuously engaged upon the topographic sheets in course of 

 construction, upon scales of one inch to eight miles, one inch to four 

 miles, one inch to two miles, one inch to one mile, and one inch to two 

 thousand feet. The number of sheets so projected as to conjoin, cover- 

 ing the entire area of survey, is 95, each 19x24 inches. Many of these 

 sheets are now complete, and thirty-two sections to be represented by 



