Februaby 26, 1904.] 



SCIENCE. 



355 



The survey as now organized is divided into 

 five branches : The geologic, topographic, 

 hydrographic, publication and administrative. 



The geologic branch includes the divisions 

 of geology and paleontology, of mining and 

 mineral resources and of physics and chem- 

 istry. The administration of the division of 

 geology and paleontology was in the hands of 

 the geologist in charge of geology, while sci- 

 entific supervision rested with the chiefs of 

 sections. The various sections included those 

 of areal geology, Pleistocene geology, pre- 

 Cambrian and metamorphic geology, petrol- 

 ogy, economic geology of metalliferous ores, 

 economic geology of non-metalliferous min- 

 erals and paleontology. A new section was 

 created during the year — that of petrology. 

 The petrographic laboratory maintained in 

 connection with this section has probably no 

 equal in the quality or the rapidity of its work. 



A new feature of the work of the division 

 of geology and paleontology was the prepara- 

 tion and publication of a bulletin entitled 

 ' Contributions to Economic Geology, 1902,' 

 which is intended to be the first of an annual 

 series. 



From the appropriation of $163,700 for 

 geologic work allotments were made for 47 

 field parties, which were sent to all parts of 

 the country. In addition to this, $14,000 was 

 appropriated for the paleontologic work of 

 six other parties. Brief accounts of the re- 

 sults accomplished by each party are given in 

 the report. 



Under authority of an act of congress ma- 

 king an appropriation of $60,000 for a con- 

 tinuation of the investigation of the mineral 

 resources of Alaska, five parties were actively 

 engaged in field work during the summer of 

 1902. A somewhat detailed account of the 

 investigations made by these parties is given 

 in the report. 



The principal work of the division of 

 mining and mineral resources is the prepara- 

 tion of the annual report on the mineral re- 

 sources of the United States, although con- 

 siderable time is devoted to answering tech- 

 nical inquiries. At the request of the 

 director of the census, the schedules of inquiry 

 of the twelfth census in regard to mining 



were included with the statistical cards an- 

 nually sent out by the survey. The returns 

 were transmitted through the Geological Sur- 

 vey to the Census OflS.ce, thus affording both 

 ofiiees the benefit of cooperation. 



The division of physical and chemical re- 

 search made 225 analyses of rocks and coals, 

 and 443 qualitative determinations of min- 

 erals during the year. A research into the 

 action of ammonium chloride on silicates was 

 finished. Experiments were made upon 

 methods for the analysis of cements. The 

 experimental work of the physical laboratory 

 related mainly to the behavior of the rock- 

 forming minerals and analogous but somewhat 

 simpler chemical compounds at high tempera- 

 tures. Experiments upon the linear force 

 exerted by growing crystals were also con- 

 tinued. 



Near the close of the fiscal year, the topo- 

 graphic branch was reorganized for adminis- 

 trative purposes into two divisions, one of 

 topography and one of geography and forestry. 

 The division of topography now includes three 

 sections : The eastern and western, and a 

 third section, subordinate to the other two, 

 which is called the triangulation and com- 

 puting section. A federal appropriation of 

 $309,200 was spent on the work, besides an 

 additional sum of $90,000 allotted by various 

 states for cooperative work. 



The year's work of the division of topog- 

 raphy may be summarized as follows : Two 

 base lines were measured; primary azimuth 

 observations were made at 4 triangulation 

 stations; 395 triangulation stations were oc- 

 cupied or located; 1,487 miles of primary 

 traverse were run; 36,275 square miles were 

 covered by detailed topographic mapping, this 

 area being distributed through 36 states and 

 territories; 29,160 miles of levels were run; 

 and 1,826 permanent bench marks were estab- 

 lished, and at each of these an iron post, a 

 bronze or aluminum tablet, or a copper or 

 aluminum plug was set in place. In con- 

 nection with the Alaskan surveys, about 20,080 

 square miles were mapped topographically. 

 About 45 miles of the boundary of the Big- 

 horn Forest Reserve of Wyoming were sur- 

 veyed and marked with special iron posts. 



