simple past tense and past participle of dream

The measurement of specific gravity by means of a pycnometer

(architecture) In Gothic vaulting, any rib which does not spring from the impost and is not a ridge rib, but passes from one boss or intersection of the principal ribs to another.

An instrument consisting of a tube containing mirrors and loose, colourful beads or other objects; when the tube is looked into and rotated, a succession of symmetrical designs can be seen.