Читать книгу Lightning Rod Conference - Various - Страница 23

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The necessity for reaching moist ground is generally recognised, but various curious ways for making earth connection are suggested. One firm considers that a band cut into strips 18 inches long would suffice, while another says that not less than 30 feet, in two or three branches, with fork at the end of each band, should be used. One firm is very brief: “Ground end is coiled loosely in damp earth or a well.” The use of coke, powdered charcoal, or carbonaceous materials, is insisted upon by others.

It is questionable whether the difficulty of fitting a good connection with the earth is fully realized. None but telegraphists know the great difficulty there is in doing this. The first object to be secured is a good damp soil, and the next as large a conducting surface as possible. Metal pumps, iron, gas, or water pipes, wells in which plates of metal 2 or 3 feet square are placed, or similar plates may be buried in perpetually damp ground, or in holes well filled with powdered coke. Moisture in some form is essential, and without it a lightning protector is of small service.