tabs n lower proportion of the " nenr-mesh " pnrticles, just smnUer than the sieve nperture size.DesiroMe sample &ze.-To determine the most suitable size for n sample for sieve nnnlysia it is therefore necessnry to nsaume tbnt the highest possible proportion of " nenr-mesh " particles is present. The experiments described nbovc (Fig. 5) show thnt snmples containing npproximntely equnl proportions of mnterinl passing nnd retained on n pnrticulnr sieve most cosily overlond thnt sieve, nud it is neaurned that this mntcrinl ie probnbly ns difficult to sieve 11s nny mnterinl likely to occur in pmctice. The required size of snmple hns therefore . been bnsed on these dntn. The snrnplc size in nnturnl snnds should therefore be such thnt the weight of mnterinl retained on m y one sieve should not exceed the following values : B.S. sieve No.