OMBROMETER, a machine to measure the quantity of rain that falls. We have the description and sign of one in Phil. Trans. no 473. p. 12. It consists of a tin funnel, whose surface is an inch square, with a flat board, and a glass tube set into the middle of it in a groove. The rise of the water in the tube, whose capacity at different times must be measured and marked, shews the quantity of rain that has fallen.