VIII. This shows a central view of âextra coilâ normally excited with streamers issuing from a disk turned towards the camera. In this instance the streamers were longer than before as they were issuing from fewer points, chiefly from the rim of the disk which was a little more than 10" in diam. Some of the streamers darting towards the corners of the building were 30 feet in a straight line, but considering their curved path they were in all probability 50 feet long. Some of them show interesting bifurcations or splitting up in many branches while others, carried by the draught they create themselves, again show clearly the individual discharges. The brilliant sparks to the hood above the coil are also curious and interesting often passing far above the hood and then returning to the same in paths much longer than the straight route from the top of the coil to the hood which they should follow. Some of the streamers striking the floor show the increased brightness, before referred to, very clearly. It is noticeable that the streamers above the coil are of finer texture and split up, the draught being of course stronger near the opening of the roof. On some of the very long streamers one can see occasionally more brilliant points. The plate in this experiment was the same as before and the vibration of the âextra coilâ system likewise normal or nearly so.
