  We present experiments on a monolayer of air-fluidized beads in which a
jamming transition is approached by increasing pressure, increasing packing
fraction, and decreasing kinetic energy. This is accomplished, along with a
noninvasive measurement of pressure, by tilting the system and examining
behavior vs depth. We construct an equation of state and analyze relaxation
time vs effective temperature. By making time and effective temperature
dimensionless using factors of pressure, bead size, and bead mass, we obtain a
good collapse of the data but to a functional form that differs from that of
thermal hard-sphere systems. The relaxation time appears to diverge only as the
effective temperature to pressure ratio goes to zero.
