I started a course of hydrology, and before the first class I noticed a mistake in the textbook: the unit of absolute viscosity is given as kg-s/m². I know that viscosity is measured in pascal seconds, and when I took his explanation of a sliding plate viscometer and figured it out, it came out in pascal seconds. What happened is that he wrote "lb-s/ft²", meaning pound force, and substituted "kg" instead of "N" for "lb". I wrote to the author, but nothing's resulted yet. Most of the measurements in the book are in foot-slug-second units.
Pierre
