Year: 1879

Some of the Causes Which Prodsce Them

 Becoming More Frequent.

 The climate of the United States. and especially the eastern portion of it, is subject to great and rapid changes. These are caused, in many instances, by the large extent of laad surface over which it's territory extends and the differ ence in the amount of solar heat received in different parts. When large bodies of SHOW have been deposited in the north the wind sweeping over them is deprived of It's heat, and lower tenn perature is the result. When winds from more southerly attitudes occur. the revt rse takes place. The vicinity of the large oceans which margin the continent of North America on the west and east also tend to produce a change, water parting with it's heat lees readily than the land. In addition to these the cur rent of warm water thrown along the east coast of the United States by the gulf stream, and in the Pacific by the sea of Japan, also exert powerful in- fuence on the climate of the United States. That waves of heat and cold travel in certain directions, and often with increasing rapidity, is generally caused by the course of chains of noun tains and the vicinity of oceans and lakes. In the States east of the Ale ghanies clouds loaded with Tain or snow generally come from the east or north, while Ill the great valley of the Missis. sippi the cold wave usually has its origin in the ice and snow covered coun- tries directly north, and periods of dronth by winds from the south.

 In European countries the cultivation of the soil and the removal of timber have produced important climatic changes, and the same has been noticed in the United States. Our winters, probably, have not so much severe weather as occurred in the early settle ment of the continent, but it takes place more suddenly and to greater extent. This is easily accounted for, as the land, when denuded of timber, presents less obstruction to the advance of storms, and also affords greater diversity of exposure in it's surface to the rays of the sun and becomes more readily and differently heated. As is well known, wind is nothing more than air rushing in to restore the equilibrium which has been disturbed by expansion caused by heat, and when the air thus moving is loaded with snow or other vapor, this, when meeting with air of different tenn perature, condensation takes place and rain or snow is deposited.

 The influence of these sudden changes on health is subject for the investiga- tion of medical men end philanthropists. That 1t has much to do in causing phys ical infruities cannot admit of doubt. A change of forty degrees of tempera- ture, such as occurred on the 2d, must aggravate all diseases of the pulmonary organs, and hence, perhaps, the extent and fatal effects of consumption in the Eastern and many of the Western States.

 Countries in which the temperature is nearest uniform, whether it be of high or low temperature, are generally least afflicted by diseases which arise from exposure to the extremes of heat and cold; while almost every portion of the habitable globe is subject to visita- tions from maladies which produce dis ease and death. These generally arise from local causes, such as stagnant water and large quantities of animal and vegetable matter undergoing decomposi- tion. They do not extend large areas, and instances of longevity in such coun- tries are not uncommon.

 The lengthening day and the restora- ton to st, of rest of the disturbed atmosphere will cause the present cold wave to be in manner temporary, but so long as large bodies of ice and snow are spread over the great lakes and large portions of the east and west, the recurrence of similar waves of cold, though not of equal intensity, may be expected to prevail.-Phitodett'hia