ROBINSON, THOMAS RODNEY - THE ROBINSON CUP-ANEMOMETER.

On the Determination of the Constants of the Cup Anemometer by Experiments with a Whirling Machine. Received March 14 - Read April 4, 1878.

(London, Harrison and Sons, 1879). 4to. No wrappers as extracted from "Philosophical Transactions" 1879 - Vol. 169 - Part II. Pp. 777-822 a. 5 plates.

First printing of Robinson's new experiments and researches into the constants of the Cup-Anemometer which he invented in 1846 by modifying Whewell's instrument by the introduction of the now-familiar windmill with hemispherical cups.

"A simple type of anemometer is the cup anemometer, invented (1846) by Dr. John Thomas Romney Robinson, of Armagh Observatory. It consisted of four hemispherical cups each mounted on one end of four horizontal arms, which in turn were mounted at equal angles to each other on a vertical shaft. The air flow past the cups in any horizontal direction turned the cups in a manner that was proportional to the wind speed. Therefore, counting the turns of the cups over a set time period produced the average wind speed for a wide range of speeds. On an anemometer with four cups it is easy to see that since the cups are arranged symmetrically on the end of the arms, the wind always has the hollow of one cup presented to it and is blowing on the back of the cup on the opposite end of the cross."

Order-nr.: 42674