Annual Report of the Director, United States Coast and Geodetic Survey to the Secretary of Commerce for the Fiscal Year Ended ...U.S. Government Printing Office, 1920 - Coasts |
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Common terms and phrases
Alaska area covered azimuth bench marks established Block Island Sound Bureau Cagayan Islands Calif Cape Cape Mendocino charts Coast and Geodetic Coast Pilot Commanding Steamer completed connection depth determined double angles DIXON ENTRANCE drag Engineers entrance fathoms feet field station fiscal Geodetic Survey geographic positions determined Harbor horizontal measures Humboldt Bay hydrographic survey inshore July Key West Lake Washington launch levels run Lighthouse located magnetic main scheme occupied maps miles of area miles of levels miles run navigation Navy necessary obtained occupied for horizontal officer operation Pacific coast Palawan pendulums permanent bench marks Point positions determined double primary triangulation progress reconnoissance reefs repairs River Romblon run while sounding San Francisco Sandakan scale season Shelikof Straits ship shoals shore line square miles stations in main stations occupied SUMMARY OF RESULTS.-Triangulation tidal tide tables tions topography traverse triangulation stations vessel vicinity Vinas River weather wire-drag
Popular passages
Page 92 - ... Canal have been prepared in pencil, and they are now being checked and traced. Additional topography in the proposed Sherburne Lakes Reservoir was taken during the year. The installation of that part of the first line of pressure pipe of the St. Mary River Crossing lying west of the river, work on which was in progress at the beginning of the fiscal year, was completed and the backfilling placed. OPERATION AND MAINTENANCE. The system operated during 1913 consisted of the upper ends of both Dodson...
Page 34 - ... methods of projection have been designed to solve the difficult problem of representing a spherical surface on a plane. As different projections have unquestionable merits as well as equally serious defects, any region to be mapped should be made the subject of special study and that system of projection adopted which will give the best results for the area under consideration. The Mercator Projection, almost universally used for nautical charts, is responsible for many false impressions of the...
Page 35 - The term conformal has been denned as follows: If at any point the scale along the meridian and the parallel is the same (not correct, but the same in the two directions) and the parallels and meridians of the map are at right angles to one another, then the shape of any very small area on the map is the same as the shape of the corresponding small area upon the earth. The projection is then called orthomorphic (right shape).
Page 95 - Capul light station, which had been loft in an unfinished state by the Spaniards. Work was continued with a force of from 60 to 90 men until last November, when the work was completed. A third-order flashing light had been installed here by the Spaniards, but had been destroyed by the insurrectos...
Page 36 - This amount of scale error of one-half of one per cent is frequently less than the distortion due to the method of printing and to changes from the humidity of the air. Only in southernmost Florida and Texas does this projection...
Page 86 - A rough control scheme was first laid out, and the mosaic constructed over this. This mosaic and also the individual photographs have been the subject of study by engineers of the survey, especially with reference to control and interpretation. Various methods of reduction for chart use were tried out. A study was made of the accuracy of mosaics and individual photographs. The possibilities of control using the photographs themselves to establish a graphic triangulation, have been investigated. The...
Page 32 - Annual Report of the Superintendent of the United States Coast and Geodetic Survey between 1894 and 1907.
Page 35 - State names and boundaries, principal rivers, capitals and largest cities in the different states, are the only information otherwise embodied. The map is of special interest from the fact that it is based on the same system of projection as that which was employed by the armies of the allied forces in the military operations in France. To meet those requirements and at the request of the Army, special publications were prepared by the Coast and Geodetic Survey.
Page 109 - ... cadastral surveys, one for triangulation, and another group would have to be organized to do topographic mapping. You would still have to have that specialization within the parties. ATTITUDE OF MEMBER OF GEOLOGIC SURVEY ON PROGRAM OF BOARD OF SURVEYS AND MAPS Mr. SCRUGHAM. Dr. Mendenhall, were you a member of the Board of Surveys and Maps of the Federal Government? Dr. MENDENHALL. No, sir. Mr. SCRUGHAM. But some member of the Geological Survey is a member of that Board? « Dr. MENDENHALL. Mr....
Page 86 - ... Government, during the past year and the rapid advance in aerial photography, first seriously undertaken during the war, now promises, with proper development, a method of surveying that will probably far exceed expectations over the old methods in rapidity, economy, and minuteness of detail. No little stress should be laid on the fact that not only are the possibilities good for an early and complete revision of our shore topography, but the opportunities that present themselves for assisting...