Arizona republican., 1910-10-12

 SUN HEAT KimbaII Says Solar Inten.
 sitg Affects Plants MAY MEAN STATION HERE Local Weather Bureau to Become Most Important In Southwest If Plans Are Carried Out - Will Direct Tucson Station

will be but a few weeks before the Phoenix station of the United States weather bureau will be one of the west With the establishing of a special meteorological sub-station at Tucson, which shall be under the su- pervision of Section Director Jesu- nofsky of Phoenix, and to whom all daily and monthly reports shall be made, and with the almost certainty that station will be established in connection with the local weather of fees for the study of the intensity of solar radiation as a preliminary to the determination of the effect of this solar energy upon plant growth, the status of the local station is certain to advance in importance and value to the department of agriculture.
 Prof Herbert H KimbalI. who is connected with the research labora of Washington, D. C., was here the greater part of last week making ob- servations of the local conditions as pertains to the solar radiation. He stated that this is d comparatively new branch of the research work con- ducted by the department of agricul ture. and is intended to ascertain just what energy exists or is controllable
 In speaking of the work, Prof. Kim ball said:
 By instruments specially devised for this purpose, We are endeavoring to determine just what quantity of heat is received from the sun in unit of time We express this in calories per minute received on a square centimeter of surface. A cal ory is the quantity of heat required to raise the temperature of one cubic centimeter of water l degree ceni- grade.
 An engineer is enabled to compute the energy in this heat just as he is able to compute the power of an en- zine or estimate the work that the sun can do in a given time. The in tensity of solar energy is one of the climatic factors, just as rainfall or temperature are factors of the climate and must have it's effect on plant growth.
 While this is a subject we have just begun to study, we have been able to pretty nearly determine that the temperature of the reflected sur face of the sun ranges from 6,700 de- grees centigrade to 1000 degrees. It is believed that research along these lines will determine what locations are best adapted climatically to the various plants. As. for instance, corn is known as a sun plant and grows more rapidly in a section where there is an abundance of sun heat.
 "There have been some observations of this kind taken in Europe as far back as 1885, These showed a marked variation, sometimes falling as much as I5 degrees below the average es- tabIished in those years. Any such marked variations in the solar inten- sity as these is bound to have it's ef- feet upon plant growth as well as upon the weather.
 "In my work here I am employing an instrument known as the Smith sonian silver disc pyrheliometer, which consists of small silver disc, black cned on the front side and placed in- side q wooden bulb with a tube in serted in one side from which it can receive radiation from the sun, all other radiation being excluded. The bulb of a bent tube thermometer is inserted in this silver disc. By eX- posing it directly to radiation for a period of two minutes and then shading it two minutes, we can meas ure the rate at which it was warmed in the sun and cooled in the shade The sum of these two rates enables us to compute the actual amount oi solar energy received upon the black ened surface of the silver disc.
 q find that the radiation here is at least per cent less at noon than it is at Flagstaff and Santa Fe, have been taking observations al Madison. Wis; Lincoln, Neb.; Chey- enne. Wyo.: Santa Fe, N. NJ; Flag staff and Phoenix. I am going to Tucson from here, but will make nc observations there. am going tc recommend the establishment of foul stations in the west from among the ! places named as having been already ! visited I cannot say that Phoenl2 ! will be recommended, nor can sa! at this time any place that l VII
 recommend"
 Prof Kimball talked very enter | tainingly of the work in which he l'
 engaged. He stated that he believed
 that the time would come when bl
 means of the information being SC cured by the research observatorA
 along these lines, the agriculture conditions throughout the entire coun' try would be very materially bene'
 fitted. He stated that the departmen
 hoped sometime to be able to instruc the farmer as to just what plants | would thrive best under certain con Il ditions. and that the energy of th' l sun heat radiation will be shown ts