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METEOROLOGICAL.

Thunderbolts and Metal Roofs.

To the Editor of the Evening Bullelin : On Thursday last, March 14th, 1878, about six o'clock in the afternoon, a thunderbolt struck the house of Mr. Joseph B. Hottel, 2019 North Twelfth street, in this city.  It struck the brick chimney of the back building and knocked a dozen or more bricks off and on to the tin roof, and drove them northeastward, showing conclusively that the bolt came from the southwestward,i.e. with the direction of the movement of the storm. The roof of the back building has no metallic connection with that of the front building, nor with the adjoining building south of it. The tin surface of the roof would not amount to more than 400 square feet-not enough to thoroughly compensate for an ordinary bolt, but enough to curtail its force to the prevention of much mechanical destruction. The tin roof is connected with a water pipe running down at the northeast corner of the building. Over and along this it browsed (I say browsed, because it eats up the surface furze of the metal) its way towards the earth. Having to make an angle of direction at this point, it played the part of any other moving thing liable to tangenital action,and a portion of it darted several feet along the brick wall, dislodging the mortar from the bricks and passed through the wall and darted into the chamber from the lath-nail heads, forcing the nails partly out of their places, and driving off the plastering at these points, which were about two feet apart, and jumping from one nail to a gas-burner a few inches off and slightly fusing its surface, and at the other point on to the metal coating of a picture frame hanging immediately above it. It blackened a portion of the frame metal jet black. Now that constituted the whole amount of its mechanical offending. There is no lightning rod on this house. I would advise the owner to connect the tin roof of the back building to that of the front building with a band of tin three or four inches broad, and then no possible damage will occur to the walls, since in that arrangement he will present metal surface sufficient to compensate for an ordinary bolt. In my last report to you I stated that I would, on a proper occasion, say something about the "Snow Harris" lightning catcher, because the lightning-rod men lay much stress upon it as an argument in favor of their rod protection. The Snow Harris rod has about as mu chrelation to their rod as a sheetiron plated ship has to an iron-clad of 12 inch plate. Snow Harris's protector consists of a broad copper band running down from the top mast to the copper on the ship's bottom. Besides this, the ship, nowadays, has much more iron in its rig and fixtures than had the ship long ago, and when lightning damage to ships was comparatively more prevalent than now. From the great amount of metal fixtures, metal life-boats, capstans and chains, the modern ship has become invulnerable to Jupiter's artillery.

The man that nowadays goes round to put up finger thick lightning-rods for protection to buildings is as much of a charletan as the man that sells amulets, or he that furnishes old horse-shoes to be nailed over stable and house doors to keep out witches. The only protecting property of the "rod" is in its surface, and that to an ordinary bolt is about as efficacious as would be a tin-foil coat of mail to thrust of a lancer's spear. The day is not far distant when a metal-covered roof will be considered as indispensable to the protection of a building and its furniture and its inmates from lightning as is the roof itself to the protection of the persons and things inside from the rain.

From over forty years' observation, I can incontrovertibly say that the thunderbolt passes from cloud to earth as any other missile would pass--shot or shell--meteorite of hail or iron, in the direction of least resistance, regardless of all and any pointers, and that when it meets a field of metal it passes over it harmless, and goes the way of all things that play out.

The fire that we see in the lightning's play is the combustion--the deflagration of the matter, diffuse or otherwise, through which the bolt passes. I have in my possession globules of iron that dripped from the end of R. R. rails along which a thunderbolt traveled. The space between the rails to allow for expansion and contraction, not over one-eighth to one-quarter of an inch. being sufficient to obstruct its velocity--air being a non-conductor to a degree of fusion of wrought iron. The atmosphere is full of diffuse matter. Interstellary space is full of diffuse iron and nickel. A magnetic storm in the regions of interplanetory space pours iron hail, and hence the deposition of masses of meteoric iron upon our planet when it happens to be the nearest body to a magnetic cyclone. I have passed through snow and hail storms in the cloud region during the hottest days of July. It often snows two to three thousand feet above the earth, and the oftenest in the hottest weather, and we are unconscious of it on the face of the earth, because it is melted and taken up as vapor in the grasp of the lower atmosphere.

We are just commencing now in the "first reader" of Meteorology, and if we stick closely to facts as nature reveals them to our senses, we shall be able, by and by, to make a respectable science of it, and learn a little of the language that the atoms use in talking to each other, as we know they do when they are gabbling one to another in their vibratory dialect as manifest in the Telephone.

JOHN WISE, 1951 N. Eleventh street.

Transcription Notes:
1) spacing matches original, but for clarity, likely meant to read as, "The Snow Harris rod has about as much relation to... 2) s/b a comma rather than a full stop: "not over one-eighth to one-quarter of an inch. being sufficient..."