A manual of practical hygiene for students, physicians, and health officers . ding: of the meter is noted, and at the expiration of the unit of time,one, five, or whatever number of minutes it may be, the reading of themeter is taken again. Permeability to Water.—The permeability of a soil to water isexpressed in terms indicating the auKnint of water which will passfrom above downward through a column of saturated soil durinor anv 358 THE SOIL. given unit of time under a given pressure. The apparatus for thisdetermination, shown in Fig. 24, consists of a metallic cylinder (tI)with a perforated
A manual of practical hygiene for students, physicians, and health officers . ding: of the meter is noted, and at the expiration of the unit of time,one, five, or whatever number of minutes it may be, the reading of themeter is taken again. Permeability to Water.—The permeability of a soil to water isexpressed in terms indicating the auKnint of water which will passfrom above downward through a column of saturated soil durinor anv 358 THE SOIL. given unit of time under a given pressure. The apparatus for thisdetermination, shown in Fig. 24, consists of a metallic cylinder (tI)with a perforated or gauze bottom on which the sample of soil is packedclosely, and another cylinder (/>), likewise of metal, provided with anumber of outlet tubes (c), at regular intervals, preferably of 5 or10 cm. The lower end of B fits tightly into the up]ier end of ^t, andthe joint is made impervious to water by means of adhesive plaster,sealing-wax, or other suitable material. The soil within the lowercylinder is kept in place, and its surface kept intact, by means of a FiQ. Apparatus for determination of permeability of soil to water. superimposed disk of gauze or coarse cloth. The outlet tubes, providedwith cocks, serve to maintain a constant level, and, therefore, a constantpressure of water as desired. Water is admitted in a constant streamto the cylinder through its upper end, by means of a rubber tube con-nected with a water faucet. If it be desired to employ the highestpressure obtainable with the apparatus, all the corks of the outlet tubes,except the upper one, are kept in place. In this case, the pressurewould be expressed by the distance l)etween the top of the soil underinvestigation and the uppermost outlet, through which the excess of EX AM/NAT/ON Oh SOILS. S-Of) water from (he faiuct is ;ill<»\v(<l lo <.-c;i[)c, hy \v;iy of ;i nihlxc liihr-loJuHn^ to ;i ,siiil<. Siinihiily, ;iiiy ollici- lici^lil, ;in<l [(rcsHUic riiav 1»«-oni|)I(»yviii<^ tli
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Keywords: ., bookcentury1900, bookdecade1910, bookpublishe, booksubjecthygiene
