The vacuum tube in a CRT can implode if it is broken or punctured. The surrounding air will rush violently into the unsealed vacuum in the CRT, spraying broken glass in every direction. Color CRTs may contain mercury or other potentially toxic materials.
Instructions. Build a hearth for a fireplace that is 16 inches deep, according to This Old House writer Harry Sawyers. This is the standard requirement for municipalities and homeowner associations. The hearth should also extend a minimum of eight inches on either side of the fireplace.
Drilled wells can be drilled more than 1,000. feet deep but domestic wells are usually between 100-200 feet in depth and 6 inches in diameter. Often a pump is pl aced near the bottom to push water up to the surface. Diagram: Drilled well in sand or gravel aquifer Diagram: Drilled well in bedrock aquifer.