Faraday to Peter Henry Berthon   20 August 1863

Royal Institution | 20th August 1863

Sir

I returned from Scotland only the day before yesterday & hence the cause of my delay in answering your letter of the 7th instant¹ which accompanied another letter from the Keeper of the lights at Lundy[.] The latter letter refers to the Extinction of all the lamps in the lower light save one during the occurrence of a Thunder storm and it attributes this effect to a very vivid flash of lightning[.] It says that it happened about 10.30.A.M. but there is no identification of the effect & the assumed cause; for the lamps were left burning properly about an hour before & were found extinguished the time of extinction not having been observed. No damage from, or marks of, lightning were visible[.] As far as I can judge it might have been some sudden effect from a gust of wind during the storm or from some door having suddenly been blown open[.] I do not know the light house & there is nothing in the description of the case that can guide me to the cause; save that a storm was on.

The effect is I suppose unprecedented and having happened but once will I suppose not happen again. It should lead to watchfulness whether any like effect in a smaller degree may occur - and to an examination of the note books whether any thing of the kind has occurred before²[.]

I am Sir | Your Very Obedient Servant | M. Faraday

P.H. Berthon | &c &c &c