Results of a magnetic-monopole search utilizing a large-area proportional-tube array.

The results of a recent magnetic-monopole search are presented. The detector is an array of He-CH{sub 4} proportional tubes whose effective area--solid-angle product is 265 m{sup 2}sr. For a live time of 578 days, no bare monopole candidates were observed, setting an upper flux limit of 1.8{times}10{sup {minus}14} cm{sup {minus}2}sr{sup {minus}1}s{sup {minus}1} (90% C.L.) for {beta}{gt}1.1{times}10{sup {minus}4}.