A simple device used to measure psychokinetic power. It was invented by the Count de Tromelin at the beginning of the 20th century. It is similar in operation to the Biometer developed by Hyppolite Baraduc just a few years earlier. It consisted of a paper cylinder with crosspiece of straw that revolved on a fine point. The movement of the human hand close to the piece of straw or the mental will of the subject was supposed to be capable of making the straw move. As with Baraduc’s device, de Tromelins ran into criticism from colleagues who argued that he had not eliminated movement caused merely by air currents or the heat of the human body. It was later superseded by similar instruments, such as the sthenometer, that were enclosed in glass, thus eliminating those criticisms.