This text goes with the picture above from Silver:
To know the perfect length of your short staff, or half pike, forest bill, partisan, or glaive, or such like weapons of vantage and perfect lengths, you shall stand upright, hold the staff upright close by your body, with your left hand, reaching with your right hand your staff as high as you can, and then allow to that length a space to set both your hands, when you come to fight, wherein you may conveniently strike, thrust, and ward, & that is the just length to be made according to your stature. And this note, that these lengths will commonly fall out to be eight or nine foot long, and will fit, although not just, the statures of all men without any hindrance at all unto them in their fight, because in any weapon wherein the hands may be removed, and at liberty, to make the weapon longer or shorter in fight(ing) at his pleasure, a foot of the staff being behind the back most hand does no harm.