| P number: | P519614 |
|---|---|
| Caption: | Specimen of roofing slate from Buttermore Green Slate Company, Keswick, Cumberland, , England |
| Description: | The company label contains information of historical interest. It describes the variety as 'No. 5 Best Ton Deep Olive Green', and states that the following sizes are available; '30 inches at the eaves to 12 inches at the ridge by proportionate Breadths, diminishing in graduated Courses, as supplied to Rochdale Technical Schools, Blackburn Technical Schools, Glossop Library, Chislehurst etc.' British Geological Survey Petrology Collection sample number EMC 5788. This information shows that at this time Cumberland slates were being produced in varying 'random' sizes, and laid on a roof in diminishing courses, as in the Scots style. Today, most English slates are produced like Welsh slates, in a uniform single size. Slate is formed by intense pressure deep in the Earth's crust related to the making of mountain chains, which bends the bedding into crumples or folds. As the folds become tighter profound physical changes take place under heat and pressure in the shales. A new set of planes is formed, termed cleavage planes, and the degree of compactness and the strength of the rock is greatly increased. Specimen size: 17x12.5cm. |
| Date taken: | 01/01/2003 |
| Photographer: | Bain, T.S. |
| Copyright statement: | NERC |
| Orientation: | Portrait |
| Size: | 150.78 KB; 775 x 1000 pixels; 66 x 85 mm (print at 300 DPI); 205 x 265 mm (screen at 96 DPI); |
| Average Rating: | Not yet rated |
| Categories: | Unsorted Images |
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