Note 85 — PART XVIII. FRICTION AND LUBRICATION.
Reading edition
The reason for this is that the effective surface of the journal A, fig. 209. which resists the pressure of the bearing, is equivalent only to the horizontal area represented by the dotted line a. b. just as the surface which resists the pressure inside of a boiler is equivalent to the diameter multiplied by its length, as was explained in answer to Question 99.