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outside and the same as recorded by the tide guage, since the oil was put into the float box. I measure the height from the surface of the oil to the bottom of the floor of the tide guage house finding it to be 19 1/4 inches - at the same time the distance from the surface of the water to the bottom of the floor, was 21 1/4 inches giving an elevation of the surface of the oil above the water level of two inches. It probably varies a little with the temperature. Day very fine and clear. Ice forming quite thick & hard by night finding irreconcileable errors in the computations from the telemeter I attempt a measurement on deck but the distance is too short for a satisfactory trial. The staff has been badly made and will have to be painted over as soon as I can get a constant for the [[strikeout]] angles [[/strikeout]] measurements already taken
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Correcton for telemeter
measurements
Focal length of Theodolite he 97
in 
7.5
object glass to center 4.5
[[line]]
additive corr. 12.in = .3048 meter

For test. Place the initial point of the chain one foot in advance of the plumbob in the direction off the staff, adding the correction to all distances measured once for each sight.
Trial on deck gives 5 units between both wires at a distance from the focal point of 16 feet 5 1/4 inches = to 1 unit between both wires at a distance of 3 feet 3 45/100 in or  0.92313 meters to which correction to the center should be added. Previous tests have omitted the focal correction and are hence erroneous. They must be repeated in a more correct way at the first opportunity