These percentages are added to the live load stresses.
Fire-damp and dust explosions are caused by the presence of marsh-gas in sufficient quantity to form an explosive mixture, or by a mixture of small percentages of marsh-gas and coal-dust, and in some cases by the presence of coal-dust alone in the air of the mine.
Most metals when molten are capable of dissolving at least small proportions of carbon, which, in general, leads to a deterioration in metallicity, except in the case of iron, which by the addition of small percentages of carbon gains in elasticity and tensile strength with little loss of plasticity.
The leading crops and their percentages of the total crop value were hay and forage (39.1%), vegetables (23.9%), fruits and nuts (11.7%), forest products (8.4%), and flowers and plants (7.1%).
The value of farms on which dairying was the chief source of income in 1900 was 46% of the total farm value of the state; the corresponding percentages for livestock, vegetables, hay and grain, flowers and plants, fruit and tobacco, being respectively 14.6, 10 2, 8 o, 4.2, 3.2, and 1 8%.
