Supply, considered by itself, is always governed by the number and producing power of those engaged in production. In other words, the amount of capital employed in a trade has much to do with the price of article produced. Besides that of good harvest there is a phenomenon very much like it in its ultimate effects; its incipient effects can, however, be seldom gauged in the manner in which those of a good harvest are gauged. A general movement in market prices based on the prospects of real scarcity or plenty, although apparently having little reference to such solid reasons for a rise or fall, is very often the result of speculation. A more curious than edifying instance of the effect of legislation has been afforded by metropolitan water companies. Protective legislation is very often source of market fluctuations, most violent in character and lasting some time before the state of demand and supply grows accustomed to the new restrictions.