Meaning of 'install' framed as placement for use; installation requires plant to be capable of operation under tax law. The term install is defined in standard dictionaries as setting up or placing an apparatus or system in position for use or service. Although not statutorily defined in the cited materials, the functional interpretation in the tax context-given the extended definition of plant-is that 'installed' means an installation that renders the plant capable of use and operation for its intended purpose.