The San Francisco call., 1898-08-07
TO FORETELL
 CALIFORNIA CLIMA TIE
Continued from Page Twenty-two.

strengthen MT. Hammond's theory ana points tc a possibility that it can be worked out to the advantage of Cah- fornia, because If we know we are go- ing to have dry year we can prepare for it and husband our resources.
 'fThe way I came to discover poSsl- ble means of foretelling our winter sea son." said MT. Hammond, was when l was making comparisons or the leHl- perature of San Francisco ana OnSa Island I was struck by the strange coincidence that the two always fol- lowed one another within certain ratio. The two extremes of tempera- ture always followed one another just three months apart, the time It taxes for the Japan current to reach here from Unga Island.
 "I then worked out chart showing the temperatures of Unga Island and the rainfall of California This also was most remarkable. l found that the higher the temperature at Unga Island in September the heavier the rainfall here in December. This did not fail 1n a single instance in all the years or which we have records.
 "Of course it must be understood that the further north the Japan cur rent sweeps the warmer it will be at Unga Island.
 My work in this line was only just beginning, as I soon found out when l
 
 temperature of Unga Island has been maintained during the past four years, showing that during the past year the , winter months averaged five degreees higher temperature than usual. Un- fortunately there are no other records known to exist from those islands or previous dry years in California, ex- cept an old Russian record from Una iaska Island. This covers the period from 1928 to 1884, inclusive. It shows that the year 1928 was abnormaHy warm. the winter months being from two to ten degrees above the normal. . No California rainfall records are in existence for that period, but in Ban croft's History of California are given statistics of grain yields at the missions along the coast from San Ra- fael to San Diego. These show general failure of these crops at all missions in 1929. the total yield being but 36,0O0 bushels. while the average annual yield for the decade 1S2130 inclu- sive was S7,250 bushels This marked failure in crops in 1929 is strong evidence of drought during the winter of 1S2S-29.
 "As further evidence of this propo- sition there might be mentioned the well-known fact that the dry winters in California are also abnormally cold winters and since the source of heat which mitigates it's temperature Is the ocean such a condition might De eS- pected when the sea has a lower tenn perature than usual.
 "Of course there may not be anything in all this. It may be merely coinci- dence, but I feel that it is worth while to test. One important factor for us to consider is the relationship that ap- parently exists between the rainfall in California and the difference between the sea and air temperatures near the California coast. In general terms it is evident that those months when the sea is colder than the land (the summer season) are our dry months, and con- versely those when the sea is warmer than the land (the winter season), are our rainy months. The amount of rain fall appears to be somewhat propor- tional to the number of degrees that the sea temperature is higher than the land This was observed by studying the records of water temperatures taken by vessels off this coast as re- ported to the hydrOgTaphic office. It was also observed by Professor George Davidson some years ago. If by any means we were able to distinguish those years when the sea temperatures would be abnormally cold we might conclude that those would be dry seasons for California
 My idea for making use or at least testing the theory would be to establish a station on one of the Aleutian islands. preferably little further west than