nected with the sidereal clock. At every alternate second, a jog is made in the line. The intervening jogs record the time of passage of a fixed star across across the meridian at Waltham is noted in the and a chronograph at Harvard University, con- the field of the transit. works' observatory on… … This clock is protected from barometrical changes by being inclosed On shelf on rear wall is the chronograph. To the left is the switch- The barometer, and, on shelf at right, the level-tester for correcting in an airtight case to which an air pump is attache*. board, for controlling the lights and…
Niagara · Croton · Water · Feet · Scientific American · Transit · American april · Sulphurous acid · Cubic feet · Rapid transit · Goat island · Power plants · American supplement · Niagara river · Spark coil
Internet Archive · Public domain (published before 1931). Free to use for anything.
