Show trees prove history repeats tree rings which tell the story ot of wet and dry seasons do not i indicate there is any general tre trend nd toward either drier or wetter climate in the pacific northwest where the united states department of 0 agriculture made studies of 1210 1240 12 10 ponderosa pines centuries old eld show that the period from 1917 to 1935 was critically subnormal because of the lack of precipitation and lower water tables fhe average ring growth from 1903 to 1919 was identical with the general overage during the past years bearing out the generally accepted theory that climatic history repeats repeals itself the ages u |