I embrace this first Opportunity that hath presented itself to return You my thanks for the very polite and Hospitable Entertaintment I met with from You when I was at Philadelphia last Year, and have deferrd it till now, that the only Subject of my Letter might not be an acknowledgment of Your Civilities, which, I believe You had rather perform than be told of. I can then write upon a Subject which is more agreeable to You, and which, for ought I know, may afford You an Occasion of publishing Your Researches still farther on the favourable Subject of Your Studies. I am furnished with the History of a Phaenomenon which may not have been commonly, if at all observed before, or is however new to me.1

Mrs. Addison a Widow Lady in our Neighbourhood2 has a large Brick House, 70 or 80 feet long, two Chimneys at each end and a Cupulo in the middle; on the Top of the Cupolo is an Iron Weather-cock the Spire of which, I believe is about 12 feet higher then the Tops of the Chimneys: The latter end of last Month there was a violent Thunder Gust from the N. W. a Flash of Lightning struck the N. E. Dormant Window, took off one Facing and broke some of the Glass, then descended down a pine Rafter to within four feet of the Foot of it, the Lightning splintered the Rafter pretty much, but here it met with a very unctuous Terpentine knot which repelled it eight feet horizontally along the Plate; the Plate is not hurt, from hence the Lightning descended perpendicularly, between the Wainscot and the Wall, into the Chamber, near an upright Window and behind a large looking Glass, some of the Mortar fell into the Window and the Shock broke some of the Glass; the Tin, near the Top of the Looking Glass, which stands aslope from the Wall, was melted, and part of the Frame, at the Bottom was burst of with such Violence as to be heave into the middle of the Floor; it did not crack the Wainscot or do any other Damage in the Chamber; it then descended into Mrs. Addison’s lodging Room, where she was then aBed and asleep, in the same Direction that it had past thro’ the Chamber, here the Wainscot was split, tho’ not splintered; within four Inches of the Southermost Frame of another Looking Glass which is directly under that in the Chamber, and within eight Inches of an Iron Curtain Rod that was hung horizontally over the Window; the Northermost Corner of this Glass was cracked, then the Lightning passed thro’ the Ground Floor a few Inches North of the Glass; it shivered the Plank and made an hole You might run Your Finger through; we could trace it no farther, for it has not even broke the white-wash under the last mentioned Perforation: The Noise waked Mrs. Addison, she observed two Balls of Fire in the Room, about the Size of Pidgeon’s Eggs which soon we[n]t out, without Noise, and left, a considerable time afterwards, a strong Sulphurious Smell in the Room.

Perhaps all these Phaenomena are accounted for in Your Book, which I have not yet had the happiness of seeing; but if they are not, You Sir, are the properest Person to recieve such communications who have had the Honour of making that useful and wonderful Discovery of the similitude between Electrical and Tonitruous Matter! A Discovery far more Philosophical and beneficial than those for which many of the Antients were Deifyed! Permit me Sir to propose some Queries: Why does not the Spire, on the Top of the Weathercock act as the pointed Wire in Your Machine and attract the Lightning from the Clouds? If You say it does, what becomes of it afterwards? for there is no Conductor continued from it to the Ground, but there are indeed, under the Vane, a great many Iron Bars curved in Different Directions: Do these Bars act as so many Conductors and so divide the force of the Lightning and alter it’s Direction as to prevent it’s doing much Damage? If we consider the several concurrent Circumstances, this will not appear an improbable Supposition: Till then we had had the longest continued Drought ever remembered at that Season of the Year; the Mercury was remarkably high in the Thermometer and consequently the Air was more crouded with the Materia tonitrualis (what ever it is) than usual: The House was never struck before, but at this time it was slightly touched in four or five different and distant parts of it. Whither a Conductor continued from one of these curved Bars would not be the likeliest way to prevent the House from Lightning for the future? What was the Conductor to the Lightning after it was repelled by the Turpentine Knot, for it has not singed the Plate; and whither there can be an estimate made between the repellent Power of the Terpentine and the attractive power of the Earth, by taking the Quantity of the Terpentine in the Knot and it’s distance from the Earth? Why was not the Lightning attracted by the Horizontal Iron Rod in Mrs. Addison’s Room? What became of the Lightning after it past thro’ the Plank which is about four feet from the Surface of the Earth? Whither the best method to secure a House which hath a Chimney at each end, is not to finish one Chimney with well glazed Bricks and the Mortar between the Bricks of the last Layer to be covered with Glass, then erect Your Machine on the other Chimney?

Pray give my Compliments to my two Countrymen, Messrs. Bonds,3 and do me the justice to believe me Dear Sir Your most obliged humble Servant