It is evident that, in such case, the string, while vibrating as a whole between its fixed extremities, is at the same time executing subsidiary oscillations about its middle point, its points B FIG.
Two pairs of muscles, apparently connected with the peduncle and its limited movements, have been minutely described by Hancock as having one of their extremities attached to this organ.
The action depends upon the difference of the pressure on the liquid at the extremities of the tube, the flow being towards the lower level and ceasing when the levels coincide.
If, for example, a knitting needle is stroked with the south pole of a magnet, the strokes being directed from the middle of the needle towards the two extremities alternately, the needle will acquire a north pole at each end and a south pole in the middle.
Its eastern and western extremities, however, receive more rain, the former being well forested, while the latter is covered with grassy cameos.