The Story of Slate - 1923 - Page 4
Engineers in power-houses and factories take great pride in the attractive appearance of the large switchboards which form an important part of the equipment wherever electricity is generated or used.
Slate slabs are attractive, and as they are easily matched in color a slate switchboard may be enlarged without detracting from its appearance.
The roof is not the only part of a building in which slate is widely used.
It may be seen in many buildings in the form of stair steps, baseboards, window sills, shower stalls, floor tile, etc.
It is also fashioned into laundry tubs, water tanks, kitchen sinks, dough troughs in bakeries and similar furnishings.
You are all familiar with slate in the form of blackboards, a use for which it excels all other materials.
It is claimed that one area in Pennsylvania, 26 miles long and 2 or 3 miles wide, provides most of the blackboard slate in the world.
Our grandparents used school slates, but they have been largely replaced in the United States by exercise books, more commonly, and I hope incorrectly, called "scribbling books."
School slates are still manufactured in great quantities, but about 90 percent of them are exported to foreign lands.
You have now had a brief outline of the origin and history of slate and its chief uses.
Let us turn to a natural ledge of slate rock as it lies in the mountain side, and follow each step in the process of shaping it into finished forms.
Slate occurs in many parts of the country and is worked chiefly in the states of Pennsylvania, New York, Vermont, Maine, Maryland and Virginia.
When a deposit of good slate is found the chief task is to remove all the soil or inferior rock from the surface leaving the good slate exposed.
The slate may be removed by blasting in drill holes, but many operators now use channeling machines to cut out massive blocks.