Assemblage and Assembly are not always interchangeable in concrete use.
Assemblage may be used freely in reference either to persons or to things.
- an assemblage of farmers from every section of the state
- an assemblage of the city’s manufactured products for exhibition
It may imply a unit that is a collection of individuals of the same general kind or one that is a whole formed by the union of miscellaneous things.
- an assemblage of logs
- an automobile is an assemblage of various distinct parts
It may be applied to something that can be seen as a unit or whole or that can be conceived as such.
- we have just been picturing nature as an assemblage of particles set in a framework of space and time
—Jeans
Assembly, on the other hand, was until recently restricted in its application to a group of persons who gather together in a given place usually for the purpose of acting as a unit or of social enjoyment or, in a more specific sense, in order to serve as a deliberative or legislative body.
- the mayor decided to call an assembly of the citizens
- the New York State Assembly
There is a tendency to use assembly instead of assemblage of a structure or machine and especially of part of a machine that is formed by the union of different parts.
- a hub assembly