Henry John Standly¹ to Faraday   30 May 1861

Waterloo Chambers. | 20, Cockspur Street, S.W. | May 30 - 1861.-

Dear Sir

We have now a lamp of a very simple nature adapted to the purposes of lime lighting in all its phases, and as the subject is one in which I know you are much interested, I venture to send you a description of it.-

It is a necessity that the face of the lime presented to the action of the blow pipe should be constantly renewed, but necessity only requires this renewal in exact proportion to the destruction of the lime.

Our original lamps were provided with clockwork to give a motion to the lime which should ensure the constant presentation of a new surface, but from the nature of a motion so obtained there is practically no relation between the consumption, and the supply, and, in order to ensure that the supply should not be less than the consumption, it happens practically that it is in excess.

To obviate this, it was necessary that the motion of the lime should be dependent upon, and regulated by the rate of its consumption only. –

We have effected this in the following manner. We have adopted the principle of a Palmers² spring candle lamp³ with this difference: instead of the candle of lime, (if I may so call it), being confined at the top by a cap, the same service is rendered by the pressure of one or more pieces of iridium (infusible by a blow pipe) pressing upon the lime immediately above the points upon which the flame impinges. One piece of iridium to each jet. - As the lime is sublimated by the action of the blow pipe a groove is formed thus removing the obstruction to the upward process of the lime by the iridium, and a new surface is constantly presented in the exact proportion required. A vast saving in the cost of the lamp and in the consumption of the lime is thus attained, and the regularity, and certainty of the light in no way diminished. I shall be happy to send one of the lamps for your inspection if you would like to see one.

I must now apologize for trespassing so far upon your time, and am Dear

Sir | your faithful servant | H.J. Standly.

Profr. Faraday.

Endorsed by Faraday: Went to see this lamp at Cockspur Street on the 4th June at 1861 [sic] – but not in use. Iridium tip to platinum wire – Seems to be a good arrangement – softening of the lime?