This paper describes the results of a beam test using the Engineering Model
of the GLAST Large Area Telescope, which was installed in a beam of positr
ons, hadrons and tagged photons at SLAC. The performance of the four subsys
tems, Anti Coincidence Detector, Silicon Tracker, Calorimeter and Data Acqu
isition will be described. (C) 2001 Elsevier Science B.V. All rights reserv
ed.