1954 Volume 32 Issue 1 Pages 11-15
The diameter of the long branch tube is enlarged as compared with that of the ordinary siphon barometer, and the diameter of the tube is even more enlarged at the surfaces of mercury, but the mercury does not break or run at any inclinations, and the force with which the mercury knocks the closed end of the tube when the tube is inclined is weakened. The height of the column of mercury is measured with small parallax by the aid of two cylinders fixed to the main scale and vernier, covering the tube at the surfaces of the mercury.
By these improvements, this barometer could be made to show the same accuracy as that of the Fortin barometer, with less quantity of mercury. It is more convenient to be carried round, and is not so often in trouble as the Fortin type.