5*4 METALLURGY OF CAST IRON. would go " white " in the one and one-eighth round test bar at the chill end, when a chill was placed on the pattern in ramming the mould which embraces such iron as is used in car wheel, chill roll, and gun metal—the author would advise the adoption of the FIG. 122.—WHIRL-GATE, TEST BAR PATTERNS AND CASTING. second or third standard bars of one and five-eighths inches and one and fifteen-sixteenths inches "in diameter described in Chapter LXIX. If the chill goes all " white " in the largest bar, he would use the largest chill block mould seen in Fig. 115, page £06, as ahould any desire to make their test bars in a " dry-sand " mould, they can readily do so, as there is no wood whatsoever connected with the flasks, thus making it practical, to place the mould in an oven to be dried. For malleable and steel testing and some speeial purposes in iron, a i4 dry-sand " mould might often be found a very good method to adopt.