Measurements of Trees. By F. Russell. 201 



a name and idea possibly derived from some previous observa- 

 tion of the effects of lightning, wben it lias struck a soil impreg- 

 nated with, iron and fused it. The development of this high- 

 colouring shows that greywacke or ancient porphyries in being 

 converted in a heated state into red sandstones, would require 

 very little additional oxide of iron to redden them. The fluxing 

 material was probably the felspar in the greywacke which was 

 discharged, leaving the alumina and quartz in the vesicular ex- 

 amples. Quartz by itself evidently requires a still higher temper- 

 ature to smelt it. The thunder-storm, which lasted a consider- 

 able time, was accompanied with torrents of rain, and a heavy 

 fall of hail-stones. A mass of these hail-stones, 2 J feet long, 1 8 

 inches broad, and 6 inches in thickness, which had slidden from 

 the roof, being covered up to protect it, remained entire in a 

 consolidated state next day. This was reported in the news- 

 papers as the remnant of a shower of ice. 



Some of the specimens of the smelted stones I picked up my- 

 self ; the rest were contributed by Mr John Wilson, Chapelhill. 



On mentioning the subject to Professor Geikie, he re-called to 

 recollection other similar phenomena, which I had almost for- 

 gotten. Humboldt found two square feet of rock on the summit 

 of Toluco vitrified by lightning ; and Saussure saw the same 

 thing on the top of Mont Blanc. In elevated sandy districts 

 vitreous tubes, or fulgorites, are occasionally formed by light- 

 ning, " which melts the sand to a considerable depth, so as to 

 form tubes, commonly sinuous, with solid and smooth walls in- 

 ternally, and rough on the outside " (Edin. New Phil. Jl. ii., pp. 

 199, 200). Darwin gives an account of the " lightning-tubes," 

 which he found intersecting the sand-dunes near Maldonado at 

 at the mouth of the La Plata. In 1828, MM. Beudant, Hachette, 

 and Savart, with a Charles's battery succeeded in the formation 

 of artificial lightning-tubes. 



Notes of the Measurements of a feiu of the larger Trees at 

 Edgerston House taken in January, 1883. By Fkancis 

 Russell, Esq., Sheriff-Substitute of Roxburgshire. 

 It was only lately that I had an opportunity to take the mea- 

 surements of some of the Trees at Edgerston, and I now enclose a 

 statement of these for the information of the members of our 

 Club. The point of measurement was about 4 feet from the 

 ground. 



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