Shows how to use a transit to locate a building correctly on the lot, plan proper grades with minimum excavation, find Building Layout Author, W.P. Jackson. Building Layout,WP Jackson. Shows how to use a transit, to locate a building correctly on the lot, plan grades with minimum excavation, find utility lines. : Building Layout () by W. P. Jackson and a great selection of similar New, Used and Collectible Books available now at great.
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Explains how to plan sewer connections, level a foundation that’s out of level, use a story pole and batterboards, work on steep sites, and minimize excavation costs.
A tube with a sensitivity reading of 8 minutes seconds would form an angle of 08′ 00″ at a radius of 2 feet 10 inches 2′” with each 2 mm movement of the bubble.
By sighting horizontally through a right angle prism, you see the point over which the biulding is centered. There are three main parts to any transit — the telescopethe leveling vialand the circle.
The vertical axis is not centered over A, even though the plumb bob might be. Concrete contractors need them for grades on floors, driveways and walks. Instruments designed for still greater precision have a vernier that further subdivides each minute into seconds.
The wind has no effect on the optical plummet; it can be a factor with the plumb bob. The TAT theodolite reads directly to 10 seconds on the optical micrometer.
There is no substitute for accurate layout of foundations, walls and floors. Purchase the most precise transit you can afford. The divisions on the circle and vernier are very fine. Set the tripod on firm ground and make sure the tripod points are stuck well into the ground. Figure shows the principle of the optical plummet.
Be sure the transit you select has the power, the precision, and the versatility you need to meet all your requirements for the present and the future.
But after setting up at A, say the instrument is not level. You may not need that degree of precision now, but you probably will need it later when your skills increase and you take on other types of jobs. The more precise instruments whose vernier or optical micrometer scales read huilding the seconds would bhilding level tubes in the 20 to 45 seconds sensitivity range. This practical handbook explains these valuable skills and shows builders and tradesmen how to use the builder’s level, plot plans, lot descriptions and surveying principles to be sure the building is in the right location and is built square, level and plumb.
This gives d instead of D. Position the tripod legs so the center of the tripod head is approximately over the centering point and the tripod head appears level.
Building Layout – W. P. Jackson – Google Books
Figure shows two theodolites, each with a micrometer scale. Shows how to use s.p.jackson transit to locate a building correctly on the lot, plan proper grades with minimum excavation, find utility lines and easements, establish correct elevations, lay out accurate foundations, and set correct floor heights. A level tube with a sensitivity of 90 seconds per 2 mm would form an angle of 90 seconds at a radius of 15 feet for each 2 mm the bubble in the tube moves.
More layour more trades are using them to save time, cut costs, and insure accuracy in their work.
Telescopes come in one of two types: The greater the precision of the transit, the more sensitive is the level tube built into it. Builring less expensive instruments have a lower power and are used for shorter range. These are extremely precise instruments.
Level tube sensitivity is explained later in the chapter.
This means that for each 2 mm the bubble moves in the tube, it forms an angle equal to the sensitivity of the arc given. An engineer normally measures angles from the north-south meridian in surveying, so the engineer’s transit is equipped with a compass.
It will be centered on different points such as a when the telescope is revolved. The degree of magnification of a telescope is called its power x. A w.p.jackeon that travels more with small movement takes longer to settle with each movement of the leveling screw.