astatic coils: an arrangement of coils used in sensitive electrical instruments; the coils are arranged to give zero resultant external magnetic field when a current passes through them and to have zero electromotive force induced in them by an external magnetic field
genus metasequoia: genus of deciduous conifers comprising both living and fossil forms; 1 extant species: dawn redwood of China; variously classified as member of Pinaceae or Taxodiaceae