W.P. Pratt¹ to Faraday   3 February 1840²

Sir,

During a storm which occurred, in the early part of last year, I was much surprized to observe the peculiar motion of the lightning. Previously it had always appeared to present to me, in its motion, acute angles or what is very commonly termed zig-zag lightning, the form always expressed by our artists, but the motion of the lightning in the present instance was in serpentine undulating lines during the whole of its continuance. So peculiar was the effect produced on me by its appearance that instead of regarding it as lightning, it appeared to me as a truly celestial display of - Electricity.

This peculiar motion seemed so different to what I have been led to understand, that you will much oblige by informing me whether it is of common occurrence, which I am induced to doubt, from its being generally spoken of as zig-zag lightning and represented as such by all our artists. If it is of rare occurrence, I shall feel much pleasure, in conveying to you further information on the subject[.]

Your early reply would much oblige | W.P. Pratt

20 Ossulston Street | Somers Town