A sad accident occurred at the Exhibition Building yesterday afternoon. At 3:15 as William A. OSBORNE of Portland (St. John) was engaged with a fellow workman, JOHNSON, in placing a rafter in position he missed his footin and fell through the interior of the building to the ground. The unfortunate man encountered several objects during his fall. About eight feet from the top he crashed through the loose boards of a staging, turned over several times in the descent and reached the ground after a fall of 37 feet. He was picked up insensible and taken in a wagon to his home on St. Paul Street, Portland (St. John) At a late hour last night there seemed to be no change in Osborne's condition and the doctor had no hopes of his recovery.