Unpublished paper, 'On the aurora' by Reuben Phillips Phillips speculates on the formation and motion of auroral arches. Since it has been found by experiment that the maximum length of the voltaic arc with a given battery is nearly the same in atmospheric air and in highly rarefied air, forming a very perfect vacuum, the author conceives that a streamer begins as a disruptive discharge of finite and very moderate length, (the maximum length very nearly of a continuous discharge,) which starts upwards from the auroral arch, which he regards as the discharging train. If this first portion is not parallel to the dipping-needle, it is moved laterally by virtue of the Earth’s magnetism, and thus wrenched from the spot where it was formed, and extinguished. Marked on front as 'Withdrawn'. Subject: Electricity / Electromagnetism Received 7 March 1856. Communicated by George Gabriel Stokes. This paper was published in full in volume 8 of Abstracts of the Papers Printed in the Philosophical Transactions of the Royal Society of London [later Proceedings of the Royal Society] as 'On the aurora'. 1856