=Temperature Gradients on Isothermal Charts of the Globe.=——The mean annual isothermal charts of the globe (see page 63) bring out some very marked contrasts in rates of temperature decrease. Thus, along the eastern side of the North American continent the isotherms are crowded close together, while on the western coast of Europe they are spread far apart. Between southern Florida and Maine there is the same change in mean annual temperature as is found between the Atlantic coast of the Sahara and central England. The latter is a considerably longer distance, and this means that the decrease of temperature is much slower on the European Atlantic coast than on the North American Atlantic coast. In fact, the rate of temperature decrease with latitude in the latter case is the most rapid anywhere in the world, in the same distance. These great contrasts in temperature which occur within short distances along the eastern coast of North America have had great influence upon the development of this region, as has been pointed out by Woeikof, an eminent Russian meteorologist. The products of the tropics and of the Arctic are here brought very near together; and at the same time intercommunication between these two regions of widely differing climates is very easy. Labrador is climatically an Arctic land, and man is there forced to seek his food chiefly in the sea, for nature supplies him with little on shore, while southern Florida is quite tropical in its temperature conditions and in the abundance of its vegetation. Between the Pacific coasts of Asia and of North America there is a similar but less pronounced contrast, the isotherms being crowded together on the eastern coast of China and Siberia, and being spread apart as they cross the Pacific Ocean and reach our Pacific Coast. In general, we naturally expect to find that the temperature decreases as one goes poleward from the equator; from lower latitudes, where the sun is always high in the heavens, to higher latitudes, where it is near the horizon, and its warming effect is less. But there are some curious exceptions to this general rule. The lowest temperatures on the January isothermal chart (-60°) are found in northeastern Siberia, and not, so far as our observations go, near the North Pole. If you find yourself at this “cold pole,” as it is called, in Siberia in January, you can reach higher temperatures by traveling north, south, east, or west. In other words, here is a case of _increase_ of temperature in a _northerly_ direction, as well as east, south, and west. Again, there is a district of high temperature (90°) over southern Asia in July, from which you can travel south towards the equator and yet reach lower temperatures.