STEP n.
space passed over by one movement of the foot in walking or running; as, one step is generally about three feet, but may be more or less. Used also figuratively of any kind of progress; as, he improved step by step, or by steps. To derive two or three general principles of motion from phenomena, and afterwards to tell…
STRONTIUM n.
A metallic element of the calcium group, always naturally occurring combined, as in the minerals strontianite, celestite, etc. It is isolated as a yellowish metal, somewhat malleable but harder than calcium. It is chiefly employed (as in the nitrate) to color pyrotechnic flames red. Symbol Sr. Atomic weight 87.3. A rad…