Winds.They will now be prepared to understand the laws treating of movements of the atmosphere. With younger classes only the more important winds should be taken, such as cyclones and anti-cyclones, land and sea breezes, trade and anti-trade winds and monsoons, whilst the older classes should be led to observe the local variations arising from peculiar circumstances.
When the principles are grasped, an exercise might be given to indicate with arrows the direction of the wind on the maps on which they have already marked the isobars.
Ocean depths.The water envelope of the world will next demand attention, i.e., the depth of the ocean and its deposits. This at first sight will appear to the children to be a subject about which they cannot possibly be expected to have any knowledge, but by a short recapitulation of the work of rivers treated in the preliminary course, the fact of the necessary existence of a continental shelf may be drawn from them, as also the fact that the breadth of this shelf will depend on the slope of the continent in the immediate neighbourhood of the coast, and on the amount of deposit made by rivers.
A wall map contoured to show depths in the Atlantic should be shown to the class, and the instruments should be described used in investigating depth and nature of the deposits on the ocean floor. With an older class the nature of the evidence with regard to the belief in the permanence of ocean basins may be touched upon.
Saltness of sea and causes regulating it. Various seas should be compared with regard to their salinity.
Tides.The tides. Their causes; spring and neap tides; reason for high tide being fifty-four minutes later each day. The subject of the tidal wave as experienced in England requires careful treatment, as many text-books leave the impression on the minds of children that the tidal wave in the North Sea travels from east to west, and that the shores of the Baltic are experiencing low tide when the eastern coast of England is having a high tide.
Currents.Currents. Causes of currents should be sought in the movements of the atmosphere. The class should be asked to indicate on the map showing winds, which they drew to illustrate a previous lesson, the effects of the trade and anti-trade winds in the production of currents. Attention must then be drawn to the way in which the position of the land modifies the currents so produced, and thus the class may gradually evolve a chart of the currents of the Atlantic. For an exercise they may be given a chart of the currents of the Pacific and asked for the causes of the direction of the currents.
Land.The teacher must then proceed to the more complex subject of the physical features of the land.
Mountains produced by folding; their position with regard to the ocean. Volcanoes and their distribution.
Hills produced by denudation.