tracer pivot arm
1test — 1. To prove; to try a substance; to determine the chemical nature of a substance by means of reagents. 2. A method of examination, as to determine the presence or absence of a definite disease or of some substance in any of the fluids, tissues,… …
2artillery — /ahr til euh ree/, n. 1. mounted projectile firing guns or missile launchers, mobile or stationary, light or heavy, as distinguished from small arms. 2. the troops or the branch of an army concerned with the use and service of such weapons. 3.… …
