THE IRKIGATION AGE. 



307 



than that of the river Nile, yet it gives fertility and pro- 

 duces luxuriant vegetation where there would be barren- 

 ness and sterility were it pure. The exception in the 

 case of .'.rrigating alkali lands would be water heavily 

 charged with alkali salts, this kind of water being one 

 of the causes of deleterious alkali deposits. 



THE SOIL AND THE ATMOSPHERE. 



The oxygen of the atmosphere is essential to the 

 germination of the seed and to the growth of the plant. 

 The whole plant must have air, the roots as well as 

 the leaves, therefore it is of consequence that this oxy- 

 gen should have access to every part of the soil and 

 thus to all the roots. This can only be effected by 

 working the land and rendering it sufficiently porous. 



Some soils absorb oxygen faster and in greater 

 quantities than others. Clays absorb more than sandy 



and the descent of dew, or the application of irriga- 

 tion water, favors this absorption in dry seasons and 

 in dry climates; it will also be greatest in those soils 

 which have the power of most readily extracting wa- 

 tery vapor from the air during the absence of the sun. 

 It must be clear from this that the influence of dews 

 and gentle showers reaches much farther than the 

 surface of the soil, watery vapor following the atmos- 

 phere down deep into the soil, penetrating as deep as 

 the porous nature of the soil will permit it. Some say 

 that, under proper conditions as to cultivation, the 

 soil will gain in dew at night nearly as much as it 

 loses by evaporation during the day. It appears rea- 

 sonable enough to suppose that the atmosphere, under 

 a pressure of fifteen pounds to the square inch, will 

 penetrate to any depth and carry with it whatever of 

 moisture and gases it contains. 



30. Ex-Mayor Peery. 

 33. Ex-Mayor Kiesel. 



HOMES OF OGDEN MAYORS. 

 31. Ex-Mayor Eccles. 



82. Present Mayor Wm. Glasmann. 

 34. Ex-Mayor Browning. 



soils, and vegetable molds or peats more than clay. 

 It depends, however, upon their condition as to por- 

 osity, and also upon their chemical constitution. If the 

 clay contains iron or manganese in the state of oxides 

 these latter Will naturally absorb oxygen in large quan- 

 tities for the purpose of combining with it, having 

 a great affinity therefor, while a soil containing much 

 decaying vegetable matter will also drink in large quan- 

 tities of oxygen to aid the natural decomposition con- 

 stantly going on. 



In addition to absorbing oxygen and nitrogen, of 

 which the air principally consists, the soil also absorbs 

 carbonic acid and portions of other vapors floating in 

 it whether ammonia or nitric acid. This absorption of 

 atmospheric elements and gases of every kind occurs 

 most easily and in greater abundance when the soil 

 is in a moist state. Hence it is that the fall of rains 



THE SOIL AND THE SUN. 



In addition to the chemical effect of sunlight upon 

 plants the rays of the sun beating down upon the earth 

 impart to the soil a degree of heat much higher than 

 that of the surrounding atmosphere. Sometimes this 

 soil heat rises from 110 degrees to 150 and more, while 

 the air in the shade is between 70 and 80 degrees, a 

 quantity of heat most favorable to rapid growth. The 

 relations between the heat of the sun and the color of 

 the soil is of little importance where sunlight abounds, 

 although in some locations it is of considerable import- 

 ance. This has already been alluded to and all that 

 need be said here is that the dark-colored soils, the 

 black and the brownish reds, absorb the heat of the 

 sun more rapidly "than the light-colored, for which rea- 

 son, as to warmth, the dark soils more rapidly pro- 

 mote vegetation than the others. 



