Spirit Leveling in Georgia, 1896 to 1914, Inclusive, Issues 631-639 |
Common terms and phrases
20 feet south 3-inch red metal 30 feet north 50 feet west aluminum tablet stamped Aransas Pass bench mark bottom of hole Brazos River bridge bronze tablet stamped cap on iron copper nail t. b. m. corner fence County Creek east of road east side feet east feet north feet northeast feet south feet west fence corner fence line Flatonia front of station Galveston highway hole in top hub t. b. m. iron post stamped Kansas & Texas Latitude longitude Marfa meters south meters west miles east miles north miles northwest miles south miles southeast miles west nail in hub nail in root north of road north of track north side post stamped Prim public road quadrangle railroad ranch red metal cap River road crossing road forks rock side of road southwest corner telegraph pole top of rail top of stone Trav triangulation station west of track west side
Popular passages
Page 106 - The office adjustment of the notes and the reduction to mean sealevel datum may so change some of the figures that the original markings are 1 or 2 feet in error. It is assumed that engineers and others who have occasion to use the bench-mark elevations will apply to the Director of the United States Geological Survey, at Washington, DC, for the adjusted values, and will use the markings as identification numbers only.
Page 250 - I), 3£ inches in diameter and one-quarter inch thick, having a 3-inch stem, which is cemented in a drill hole in solid rock in the wall of some public building, a bridge abutment, or other substantial masonry structure. The second form (F, PI.
Page 4 - This level is not the elevation determined from the mean of the highest and the lowest tides, nor is it the half sum of the mean of all the high tides and the mean of all the low tides, which is called the half-tide level. Mean sea level is the average height of the water, all stages of the tide being considered. It is determined from observations made by means of tidal gages placed at stations where local conditions, such as long, narrow bays, rivers, and like features, will not affect the height...
Page 4 - To obtain even approximately correct results these observations must extend over at least one lunar month, and if accuracy is desired they must extend over several years. At ocean stations the half-tide level and the mean sea level usually differ but little. It is assumed that there is no difference between the mean sea level as determined from observations in the Atlantic Ocean, the Gulf of Mexico, or the Pacific Ocean. The connection with tidal stations for bench marks in certain areas that lie...
Page 3 - For primary lines standard Y levels are used; lines are run in circuits or are closed on precise lines, with an allowable closing error in feet represented by...
Page 3 - The bottom is spread out to a width of 10 inches in order to give a firm bearing on the earth. A bronze or aluminum-bronze cap is riveted over the top of the post, which is set about 3 feet in the ground.
Page 250 - ... were eliminated. This level is not the elevation determined from the mean of the highest and the lowest tides, nor is it the half sum of the mean of all the high tides and the mean of all the low tides, which is called the half-tide level. Mean sea level is the average height of the water, aU stages of the tide being considered.
Page 5 - COUNTIES. The elevations in the following list were determined by primary leveling extended from the precise-level line of the Coast and Geodetic Survey along the St.
Page 4 - It is determined from observations made by means of tidal gages placed at stations where local conditions, such as long, narrow bays, rivers, and like features, will not affect the height of the water. To obtain even approximately correct results these observations must extend over at least one lunar month, and if accuracy is desired they must extend over several years. At ocean stations the half-tide level and the mean sea level usually differ but little. It is assumed that there is no difference...
Page 106 - The numbers stamped on the bench marks described in the following pages represent the elevations to the nearest foot as determined by the levelman. These numbers are stamped with 3/16-inch steel dies on the tablets or post caps, to the left of the word 'Feet.