A matrix of wood or iron is covered with successive layers of papers, pasted together so as to form pasteboard.
The Montana sapphires and the matrix have been described by Dr G.
If the matrix, however, is originally crystalline it does not seem probable that perlitic structure can develop in it.
When mixed the concrete is carried at once to the position required, and if the matrix is quick-setting Portland cement this operation must not be delayed.
Here let us recognize that what gives this transfer of carbon from graphite skeleton to metallic matrix such very great influence on the properties of the metal is the fact that the transfer of each 1%.