Weather not only influences most kinds of business, but is the foundation of many of them. Plenty of illustrations of the latter fact will be found in every large department store. Umbrellas, rubbers, and mackintoshes are made and sold because of rain; their best market is in countries with rainy climates, and their sale from day to day fluctuates with the state of the sky. Electric and palm-leaf fans are a drug on the market or the reverse, according to the readings of the thermometer. Sleds and ice skates are sold where and when the weather is cold. This list may be prolonged _ad lib_. If we leave the department store and walk along any business thoroughfare, we shall discover other striking examples of commercial undertakings that owe their existence chiefly or entirely to the weather. Abolish cold weather and you abolish the dealer in furnaces and heating stoves, besides reducing the rank of the coal-dealer considerably below the “baronial” level. Eliminate hot weather from the meteorological program and the ice dealer will likewise tumble from his high estate. All this is so obvious that it seems hardly worth while setting down; and yet the paradox must somehow be explained that business men have not, in general, paid much attention to meteorology, and that they have made only fragmentary use of the official meteorological establishments that were created, in part, for their benefit. Probably this paradoxical situation is merely a case of mental inertia. During the long ages of traffic before there were any weather maps, scientific weather forecasts, or climatic statistics, the weather was necessarily an unknown quantity in the mathematics of buying and selling. That it is not so to-day is a fact to which the business mind has been very slow in adjusting itself. We have mentioned some of the obvious relations of weather to commerce, but there are others that are not so obvious. Many of these are indirect. Thus the effects of the weather on agriculture are nearly always reflected in the commercial world. It is not the farmer alone who suffers from a prolonged drought, for example. It has been asserted that every severe financial panic in our history has been closely associated with a protracted period of deficient rainfall, and that there has been no period of protracted drought without a severe financial panic except one that occurred during the Civil War. Mr. H. H. Clayton, who published this assertion in 1901, has cited the case of the wheat crop as illustrating the magnitude of the effect that rainfall exercises on economic conditions in general through its effects on agriculture.