Those are the pressures listed in the Clymer manual for the original tires. Bridgestones I think??
Check your tires for max pressures listed on the sidewall, and govern yourself accordingly.
The above pressures are probably good guidelines for starting pressures on most tires.
FWIW, I read of another method of finding the right pressure for you and your bike and tire combo on a highway ride.
Record the pressure when cold and parked in the garage or the shade before riding for the day.
After 30-40 minutes of riding, the pressure should rise by 3 psi.
If it rises more than that, initial pressure was too low and the tire flexes too much creating heat and undue wear of the sidewall.
If it rises less than 3 psi, the tire was inflated too much initially, traction will be less than optimum, and the ride will be harsher than neccesary.