THE ELOW OE SOLIDS.

95

central jet, and that they bent over from tbis area so as toflow into the jet simultaneously, the external sui'face beingformed of the bottom disc, which has assumed the shape of acylindrical covering. The other layers form separate tubes con-centric with the jet, all being closed at the outer end by a capformed of the central part of the disc.

A further experiment with a cylindrical block having asmaller height, compared with the diameter of the orifice, gavea result as shown on figs. 18 and 19.

ö

HötUnv Jet jTrodfueJ' from/ 4 Disc# cf ZeaeEflotving Oxrac/flv ccnceniriey circdlar orificeand/ formxng eenlracied- vein /.

Uollenv Jet/ j/redaeej fnmv Z J)isc$ of ZeaJ/flowxng throi’tfli/ cmctmtrüy cirxiüar orificeand* forming coritraeUxT/ vein/.

The orifice in these two cases was l - 58 inch diameter, andeach disc was 0T2 of an inchthick. DD (as before) was theoriginal position of the layers.

It is interesting to notice thatthe diameter of the jet is notthat of the full diameter of theorifice, but a “ vena contracta ”has been found, such as occursin the flow of liquids. In fur-ther experiments the undula-tions which were observed inthe metal corresponded withthe relative motions of thepartieles of a similar vein offluid.

Many other metals thanlead were subject to pressurethrough an orifice, and thegeneral conclusion arrived atfrom theni was, that the par-ticles of solid bodies flow under pressure similarly to liquids.Any alteration in the shape of the orifice, from the circularto the polygonal, or eccentric, produced torsional movementsof the metal corresponding to the gyratory movements whichoccur in the flow of a liquid through an orifice, which is notplaced symmetrically to the sides of the vessel containing it.

Figs. IS and 19.