11 



of territory, in Monterey, Santa Barbara, and San Luis Obispo Counties. 

 The information obtained from time to time- during the progress of the 

 survey has been added to it, and it is now completed as far as the fifth 

 standard line south of the base line. A party would be able to finish the 

 fieldwork remaining to be done on this map in two seasons, or six 

 months of fieldwork. 



(d) St'ftle of ten miles to one inch. This will probably be the scale 

 adopted for the final general map of the whole State, and this map 

 would be about five feet square, in four sheets, and would also necessarily 

 embrace a large portion of Nevada, unless the space were designedly 

 left blank. For this map we have already a large amount of material, 

 comprised in not less than one hundred sheets, portions of which have, 

 of course, been used in the other maps now in progress. All these sheets 

 should be looked on as so much plane table work, to be compiled here 

 after and co-ordinated by a system of carefully conducted astronomical 

 observations, which will fix the position of a considerable number of 

 points on the different sheets with great accuracy. Until this is done 

 we can never have even a tolerable map of the whole State, as there are 

 errors and discrepancies in the work of the United States Land Office 

 which can only be cleared up by a careful series of astronomical obser 

 vations. The portions of the State where most remains to be done in the 

 topography are the southeastern and northwestern corners, regions the 

 most thinly inhabited of any, and where Indians have frequently been 

 very troublesome. 



2. PHYSICAL GEOGRAPHY. 



The collection of materials in this department has gone on uninter 

 ruptedly. The number of barometrical observations for the determina 

 tion of absolute heights of important points, has greatly increased during 

 the past two years. The important investigations of Colonel R. S. 

 Williamson in regard to the fluctuations of the barometer on this coast, 

 are now in process of publication ; and when this volume shall have 

 been completed, it will be advisable for us to commence a systematic 

 revision of all our barometrical works, and to publish the final connected 

 results in a tabular form. We shall be able to give a close approximation 

 to the heights of between one and two thousand points in this State, 

 including all the higher mountains and most of the towns and mining 

 camps. To compute the observations already made will, however, 

 require not less than a year's unremitting labor; but the results will be 

 of great practical as well as scientific value. 



We have continued the investigation of other subjects connected with 

 the physical geography of the State. Among them, the nature and dis 

 tribution of the forest trees may be mentioned, as of peculiar interest. 



A beginning has been made in the construction of a map on which the 

 boundaries of the areas occupied by the principal groups of trees are 

 laid down. 



3. GENERAL GEOLOGY. 



For the reasons stated above, much less progress has been made in the. 

 strictly geological than in the topographical department Still, a very 

 considerable amount of work has Been done, as will be seen from the 

 above synopsis of the operations and movements of the various parties 

 during the past two years. This synopsis will also show where, when 

 and by what persons the geological work has been executed. 



