To David Hume
Dear Sir, London, May 19. 1762.
It is no small Pleasure to me to hear from you that my Paper on the means of preserving Buildings from Damage by Lightning, was acceptable to the Philosophical Society. Mr. Russel’s Proposals of Improvement are very sensible and just. A Leaden Spout or Pipe is undoubtedly a good Conductor so far as it goes. If the Conductor enters the Ground just at the Foundation, and from thence is carried horizontally to some Well, or to a distant Rod driven downright into the Earth; I would then propose that the Part under Ground should be Lead, as less liable to consume with Rust than Iron. Because if the Conductor near the Foot of the Wall should be wasted, the Lightning might act on the Moisture of the Earth, and by suddenly rarifying it occasion an Explosion that may damage the Foundation. In the Experiment of discharging my large Case of Electrical Bottles thro’ a Piece of small Glass Tube fill’d with Water, the suddenly rarify’d Water has exploded with a Force equal, I think, to that of so much Gunpowder; bursting the Tube into many Pieces, and driving them with Violence in all Directions and to all Parts of the Room. The Shivering of Trees into small Splinters like a Broom, is probably owingto this Rarefaction of the Sap in the longitudinal Pores or capillary Pipes in the Substance of the Wood. And the Blowing-up of Bricks or Stones in a Hearth, Rending Stones out of a Foundation, and Splitting of Walls, is also probably an Effect sometimes of rarify’d Moisture in the Earth, under the Hearth, or in the Walls. We should therefore have a durable Conductor under Ground, or convey the Lightning to the Earth at some Distance.
It must afford Lord Mareschall a good deal of Diversion to preside in a Dispute so ridiculous as that you mention. Judges in their Decisions often use Precedents. I have somewhere met with one that is what the Lawyers call a Case in Point. The Church People and the Puritans in a Country Town, had once a bitter Contention concerning the Erecting of a Maypole, which the former desir’d and the latter oppos’d. Each Party endeavour’d to strengthen itself by obtaining the Authority of the Mayor, directing or forbidding a Maypole. He heard their Altercation with great Patience, and then gravely determin’d thus; You that are for having no Maypole shall have no Maypole; and you that are for having a Maypole shall have a Maypole. Get about your Business and let me hear no more of this Quarrel. So methinks Lord Mareschal might say; You that are for no more Damnation than is proportion’d to your Offences, have my Consent that it may be so: And you that are for being damn’d eternally, G —- d eternally d — n you all, and let me hear no more of your Disputes.
Your Compliment of Gold and Wisdom is very obliging to me, but a little injurious to your Country. The various Value of every thing in every Part of this World, arises you know from the various Proportions of the Quantity to the Demand. We are told that Gold and Silver in Solomon‘s Time were so plenty as to be of no more Value in his Country than the Stones in the Street. You have here at present just such a Plenty of Wisdom. Your People are therefore not to be censur’d for desiring no more among them than they have; and if I have any, I should certainly carry it where from its Scarcity it may probably come to a better Market.
I nevertheless regret extreamly the leaving a Country in which I have receiv’d so much Friendship, and Friends whose Conversation has been so agreable and so improving to me; and that I am henceforth to reside at so great a Distance from them is no small Mortification, to My dear Friend, Yours most affectionately
My respectful Compliments if you please to Sir Alexr. Dick, Lord Kaims, Mr. Alexander, Mr. Russel, and any other enquiring Friends. I shall write to them before I leave the Island.