Typescript (photocopy).A search for superheavy grand unified (GUT) magnetic monopoles has been performed utilizing a large (260m²sr) array of scintillation counters, sited underground at a depth of 1200 m.w.e. This apparatus measures both the time of flight and specific ionization of particles passing through it and has a trigger which is sensitive to prompt as well as very slowly developing pulses from the detector. No monopole events have been observed during 280 days of live time operation of this detector. An upper limit on the flux of monopoles of 4.6 x 10⁻¹⁴cm⁻²sr⁻¹s⁻¹ is obtained in the velocity range 8.5 x 10⁻⁴c to 0.012c at a 90% confidence level
