[1] Errors can be avoided and translation between the systems facilitated by labelling all physical quantities consistently with their units.
[5] Everett (1861) proposed the metric dyne and erg as the units of force and energy in the FPS system.
Latimer Clark's (1891) "Dictionary of Measures" contains celo (acceleration), vel or velo (velocity) and pulse (momentum) as proposed names for FPS absolute units.
[9] Together with the fact that the term "weight" is used for the gravitational force in some technical contexts (physics, engineering) and for mass in others (commerce, law),[10] and that the distinction often does not matter in practice, the coexistence of variants of the FPS system causes confusion over the nature of the unit "pound".
Its relation to international metric units is expressed in kilograms, not newtons, though, and in earlier times it was defined by means of a mass prototype to be compared with a two-pan balance which is agnostic of local gravitational differences.
[1] To convert between the absolute and gravitational FPS systems one needs to fix the standard acceleration g which relates the pound to the pound-force.
[citation needed] While g strictly depends on one's location on the Earth surface, since 1901 in most contexts it is fixed conventionally at precisely g0 = 9.80665 m/s2 ≈ 32.17405 ft/s2.