During the latter part of his life Coulomb contributed to varying topics- including electricity, magnetism, friction, and torsion. Coulomb wrote papers on these topics including the following.
Coulomb's paper entitled "Theorie des machines simples" was an analysis on friction in machinery. He also wrote about a series on experiments in friction based on his work while working at shipyards. In fact, according to some Coulomb was quite influential in the creation of the science of friction, and that "without exaggeration, one can say that he created this science." (6) He took a particular interest in the friction, both static and dynamic, in sliding surfaces and in bending and rolling cords.
In one particular memoirs, Coulomb showed his wealth of engineering knowledge, discussing topics from the rupturing of masonry piers, to the design of vaulted arches, to the theory of earth pressure. With the sliding wedge theory he developed still in use today in basic engineering analysis of soil mechanics. However, his routine use variational calculus in his solutions instead of giving numerical solutions to the problem, may be a reason why more focus has not been placed on his engineering theories.
Later in his life, Coulomb would assist in the creation of a metric system of weights and measures. Where his name would eventually be adopted as the unit of electrical charge in the SI system. Coulomb's contributions to our understanding of electrical and magnetic properties along with the instruments he developed, make him an invaluable asset to modern physics.