David White Pocket Sighting Level 17-620

This level will quickly and easily approximate the level of retaining walls, batter boards, fences, etc. For these operations, set a leveling rod, folding rule, or length of stick on the object to be checked. Sight through the level (hold level close to eye and look through small opening at rear of level). NOTE: Do not cover level vial opening with your fingers. This will prevent light from entering, making it difficult to see the bubble. Raise or lower front end of the level until the bubble is centered on the long center line on the object window. Readings can be made easier and more accurate if a level rest is used. A 1x2 board cut to a convenient height is adequate.

Determining Differences in Elevation
Place the leveling rod or stick at a convenient distance. Sight through the eyepiece and with bubble centered, note or mark reading on rod or stick. For example: First reading on rod is 5ft. Move rod to new location and take a second reading. This reading is 3ft. Difference in elevation between the first and second reading is 2ft.

Large differences in elevation are determined as follows:(1)Measure the difference from the ground to your eye while standing comfortably erect.
(2)Start at the base of a slope and sight through eyepiece. (3)Mark the spot on the slope where the level line of the sight shrikes the ground. (4)Move up to this location and sight again. (5)Repeat same procedure until the top of the slope is reached. Total numbers of sightings multiplied by the distance from ground to your eye totals difference in elevation.

Estimating Distances
The distance between the top line and the bottom line on the object glass is equal to a ratio of 1:12. If the user is looking at a sighting rod and the top line crosses the rod at 5 ft. and the bottom line at 4ft. The user is 12 ft away from the rod.
5ft-4ft = 1ft     1ft x 12 = 12ft

If the distance is so great that you cannot read the numbers clearly, have the person holding the rod point to a starting mark. Tilt the pocket level until the bottom line crosses the rule at his finger. Then he can slide his finger up the rule to where it crosses the top line. He can then give you the readings and you can determine the distance.

Setting Wall Tiles in a Level Line
Rest the pocket level on a convenient surface or stand erect holding it to your eye, and sight through the pocket level at the wall to be tiled. When bubble is centered on the long center line, mark wall in line with the long center line. Repeat this step one or more times along wall. By measuring up or down from these marks to the height desired, you have a level starting line.

Setting Fence with Level Top
Drive two poles into the ground, one at each end of the fence location.
Poles should be tall enough to sight without stooping over. Rest the pocket level on convenient surface or stand erect holding it to your eye and sight on one of the poles. When the bubble is centered on long center line, mark pole in line with the ling center line. Repeat on second pole, sighting from the same position. By measuring up or down from these marks to the height desired, you have a level line for the top of your fence.

Grading a Driveway
Establish roughly the ends of the driveway and drive poles into the ground every ten feet. Poles should be tall enough to sight without stooping. Sight the nearest pole. If you are standing at the upper end of the driveway and desire a 1/4" per foot grade, center the bubble on the first line below the long center line and mark the pole in line with the long center line. Sight each pole in the same way from the same position. If standing at lower end of the driveway, use the first line above the long center line. Drive a stake into the ground next to the first pole so the top of the stake is at the desired driveway height. Next, measure from the mark on the post to the top of the stake. Drive stakes next to each of the poles and set them so the tops are the same distance below the mark you established on the first pole.
The stake tops now correspond to the grade of 1/4" per foot. For a 1/2" per foot grade use the second line above or below the long center line.

Establishing a Slope
For setting grades other than 1/4" or 1/2" per foot(see above), drive poles into ground at equal distances every ten or twenty feet or other convenient distance. Rest pocket level on convenient surface or stand erect holding it to your eye and sight the first pole. When bubble is centered on the ling center line, mark pole in line with the long center in line. Sight each pole the same way from the same position. These marks are now level. By measuring an amount equal to the slope required from these marks, you can establish a line for any slope.

Contour Farming and Terracing
Set a leveling rod or stick at the point where the furrow will be started in the field. Sight in the rod or stick and mark the position with a narrow strip of cloth or target. Drive a stake at this spot. Move the rod or stick to the next convenient location. By moving up or down the slope until a level line of sight hits the cloth or target, the point along the contour is determined. When a furrow is plows between the two stake points the elevation will be the same at both points.