The weekly examiner., 1901-07-27

numbering, their effects on forest pro- duction and on the adjacent agricul- l tural lands. The effects of forest fires on the forest land and the relation of such denudation to the flow of water l in streams and the supply of water for irrigation is fully shown. The
 principal types of trees and forests are illustrated to show the size and lumber production of forests occupy
 ing agricultural and nonagricultural lands. The value of preserving certain types of protective forests on water
 sheds for the conservation of water important to large areas of agricul- tural lands is illustrated. A special feature of the photographic display is the illustration of individual trees, of the mammoth big trees, the giant red frs, white frs and the sugar pines of the California Sierras by colored
 transparencies. Ii" is interesting to state in this connection that these transparencies are the largest ever
 made. Typical agricultural valley lands in the east and west are illus trated son the same scale, showing the special protective agencies of natural adjacent mountain forests and, plant GU Sne1ter DeI9S OI 1OTeSL trees. l He
 region and the subject from which
 these illustrations were taken are rep
 resentative of the principal agricul-
 tura1 and forest sections of the United States.
 The progressive agriculturist will be interested in the exhibit of the divi-
 sion of botany, as it relates to one of
 the first essentials of his calling. The
 exhibit represents the work of the
 seed laboratory at the department of
 agriculture, where samples of all
 seeds distributed by the government
 are now carefully tested for purity,
 germinability and freedom from seeds
 of noxious weeds. Thousands of sam
 pies from farmers and seedsmen in all
 parts of the country are also tested
 at this laboratory. The work is of
 special interest to farmers, gardeners,
 seedsmen and experiment station
 workers, to whom the subject of pure seeds is of vital importance. The seed
 Ia boratory of the department of agri-
 culture is we'll recognized IS the most
 important seed testing station in
 America. It's methods, standards and
 most important pieces of apparatus
 have been adopted for seed testing
 at many of the state experiment sta tions.
 On entering the space devoted to
 this exhibit at the left of the main aisle one sees first in glass case a
 purity separating table with magni-
 flying glass, forceps and other tools
 used by experts of pure seed, chaff,
 sand and other foreign matter and weed seeds. Next is a pair of fine
 balances on which samples are weighed, all percentages in seed pur-
 ity tests being based upon weight. Beyond the scales is new combined mixer and sampler. In this a quan- tity of seeds is quickly mixed and a
 sample of the desired amount deliv- cred which will fairly represent the
 entire lot.. One. of the most Eac- tive pieces of apparatus usedsin pur- ity testing is the blast impurity sep arator, which is also a new device. The air blast is furnished by a modern blower driven by an electric motor. The device itself, however, in which the separation of chaff and lighter inn purities from seed is performed through the action of an air current, consists of a simple bent glass tube connected with a receiver.
 Actual germina tion tests are carried on at the exposition as in the seed laboratory at Washington. Conner cial seeds are counted, arranged in folded blue blotters, moistened and placed in the standard germinating chamber, where they are kept at fixed temperatures favorable to germina- ton. Check germin la tion tests, such
 Sr with many kinds of seeds, are made in sterilized sand and soil in greenhouse "fats.'' The number germinating each day for definite period in each of the tests are noted and the per- centage of germination thus com puted.
 Many weeds the seeds of which are most frequently found as impurities in commercial seeds are represented by living plants, labeled with the names by which they should be desig I mated by English speaking people ! wherever found. A unique feature is an exhibit of seeds of many of these l weeds and also several kinds of com 1 mercial seeds arranged under 40 mag I nifying glasses, accompanied by seeds l of the same kinds in open dishes, so that one may readily compare the ma gnified impression with the actual ! seed and note differences and distinc- tive characters that would not appear l to the unaided eye.
 The results and importance of seed l testing are graphically represented by several groups of glass tubes con- ] taining different kinds of commercial | seeds. These show the ordinary com l mercial seed, the amount of pure seed | true to name in the sample and the l amount of inert matter, such as chaff, | sticks and sand, the proportion of | weed seeds and finally the amount of |