282 TRANSACTIONS OF THE 



HYPOTHESES. 



Hypotheses are imaginative efforts to overcome difficulties, and their use 

 is fully justified by experience. 



First — It is claimed that the heat and dryness of the north wind are 

 communicated to it by the dry plains and stubble fields of the Sacramento 

 Valley; and in support of this hypothesis it is said that the north wind 

 does not become peculiarly vicious until after harvest. The objection to 

 this hypothesis lies in the supposed fact, probably true, that the north wind 

 is more vicious just where it first touches the Sacramento Valley than after- 

 wards, and that its exasperating qualities decrease as the current moves 

 southward. As my personal observations of this wind have been confined 

 to Sacramento and the Bay of San Francisco, I am not able to determine 

 the question at issue. One thing, however, is certain: I have received 

 descriptions of the evil effects of the north wind as far south as Stockton, 

 which could not be surpassed by any similar occurrences at the north end 

 of the valley. But no matter how much truth this hypothesis may con- 

 tain, it does not explain the cause of the exasperating characteristics of 

 the north wind as felt at the extreme north end of the valley. 



Second — Dr. Cameron states another hypothesis: ''The heat of the north 

 wind in Summer time seems to be communicated to it from the lava, beds 

 of Northern California, as I am informed that above Yreka they begin to 

 be pleasant winds, even in the hottest Summer months." The Rev. Ed. L. 

 Green, of Yreka, says: " We have north winds, though no high winds from 

 that quarter. They are cold, bringing frosty nights, sometimes even in 

 June. Later, after the warm weather sets in, they effect an agreeable 

 change in the temperature. We have no wind here corresponding to the 

 dry, disagreeable north wind that blows down the Sacramento Valley." 

 As Yreka lies due west of the lava beds, so as not to be influenced from 

 that direction, the second hypothesis may yet be established. 



TJtird — A third hypothesis is offered. In this it is claimed that the 

 wind which sets into the Gulf of California passes up through the arid 

 plains of Arizona northward, curving westerly and then south, entering the 

 head of our great valley; and that the heat and other disagreeable quali- 

 ties of the north wind are derived from the plains of Arizona and interven- 

 ing deserts. Of this hypothesis it is sufficient to say that we are not yet 

 in the possession of established facts with which to sustain it in a scientific 

 manner. 



Fourth — I think we will make better progress by separating the subject 

 of causation, and by simply considering, first of all, the cause of the dry- 

 ness of the north wind, without any reference to its other disagreeable char- 

 acteristics. The dryness of this wind is partially explained by the fact 

 that it passes over lava beds and dry mountains. Indeed, during the Sum- 

 mer all the mountains of California, even where they are not denuded, are 

 gigantic dust heaps. 



Fifth — It is probable, however, that the northerly winds have their origin 

 in the far western Pacific Ocean, and it is claimed by observing travelers, 

 that they are exceedingly dry in Summer time, far out from our coast. 



Sixth — But all dry winds are not necessarily evil in their effects. We 

 have, then, to account for their disagreeable and pernicious qualities. And 

 for this purpose we resort to a sixth hypothesis, which depends for its sup- 

 port chiefly on the dryness of the north wind. For the sake of convenience, 

 we call this the electrical hypothesis. Electricity is capable of being 

 massed, condensed, rarified, and also of discharging itself. It exists in 



