523,380. Furnace grates. ESKE, F. W. Jan. 4, 1939, No. 286. [Class 51 (i)] The firebar described in Specification 501,976 is modified by forming the surfaces 7 which abut against the corresponding surfaces of adjacent bars without inter-engaging parts so that it may be removed without disturbing other bars and by forming the bosses 8 with open recesses to engage the bolts holding the grate bars in position.' Specifications 469,799 and 482,221 also are referred to.