This section is from the book "Cyclopedia Of Architecture, Carpentry, And Building", by James C. et al. Also available from Amazon: Cyclopedia Of Architecture, Carpentry And Building.
One of the groups of mineral substances composed of different hydro-carbons, which are widely scattered throughout the world, is known as bitumen. There is a great variety of forms in which bitumen is found, ranging from volatile liquids to thick semi-fluids and solids. These are usually intermixed with different kinds of inorganic or organic matter, but are sometimes found in a free or pure state. Liquid varieties are known as naphtha and petroleum; the viscous or semi-fluid as maltha or mineral tar; and the solid as asphalt or asphaltum.
The most noted deposit of asphaltum is found in the island of Trinidad and at Bermudez, Venezuela. Deposits of nearly pure asphaltum are found in Utah, Mexico, Cuba, and different parts of the United States. Varieties of nearly pure asphalt are known as wurtzilite, elaterite, and gilsonite.
The bituminous limestone deposits at Seyssel and Pyrimont, France; in the Val-de-Travers, Canton of Neuchatel, Switzerland; and at Ragusa, Sicily, are known as rock asphalt. It is more durable than asphaltum, and is extensively used in Europe for paving purposes.
There are two forms in which rock asphalt is prepared for shipment:
(a) Compressed asphalt blocks, which are used in about the manner of stone blocks.
The mastic asphalt is used for waterproofing and damp-proofing purposes. For all work of this kind, the Val-de-Travers, or the Seyssel, or Sicilian rock asphalt should be used.