Obs. [mod.L. dim. of terra earth: cf. L. terrula, and see -EL2.]
1. A little Earth; a small orb or planet.
1657–83. Evelyn, Hist. Relig. (1850), I. 162. Only signifying His making greater worlds, and not these microcosm terrellas.
1682. H. More, Annot. Glanvill’s Lux O., 141. I should rather suspect … that the Fire will more and more decay till it turn at last to a kind of Terrella, like that observed within the Ring of Saturn. Ibid., 142. To let its Central Fire to incrustate it self into a Terrella.
2. A spherical magnet, having like the earth two magnetic poles; sometimes, for experimental purposes, marked with lines representing the earth’s equator, meridians, parallels, etc.: used to illustrate the dipping of the needle, and other phenomena of terrestrial magnetism. Also, a small artificial globe having a magnet within it, which behaves in the same way, and serves the same purposes.
1613. M. Ridley, Magn. Bodies, 4. The first form of the Magnet … is a large one in fashion of a round ball, boule or globe, and we do call it a Terrella.
1646. Sir T. Browne, Pseud. Ep., 62. The Terrella or sphericall magnet geographically set out with circles of the Globe.
1773. Lorimer, in Phil. Trans., LXV. 79. Whenever any one meets with a terrella, or spherical loadstone, the first thing he does is to find out its poles.
1822. Imison, Sc. & Art, I. 405. A small globe, having a magnet enclosed within it, which … is called a terrella.
1837. Brewster, Magnetism, 304. Shape it … so as to give it any form…, whether of a terrella,… or any other.
