Ron, You're right. An analemmatic dial tells time by the azimuth of the sun. The actual height of the gnomon is of no real import. The time is determined from the angle the shadow makes with the meridian.
There is a different approach to a dial which does require knowing the height. That is to use the standard hour-lines of a traditional horizontal dial and place an individual of height x at a distance x cot(lat) along the meridian away from the dial center. Then the shadow of the top of the person's head will fall on the hour lines at the appropriate place to note the time. But these two dials are totally different - constructed differently and work on very different principles. The analemmatic uses hour-points; the other uses the usual hour-lines. Fred Sawyer North American Sundial Society
