**Nb** Va Vb FIG.

COLUMBIUM, or Niobium (symbol Cb or **Nb**, atomic weight 94), one of the metallic elements of the nitrogen group, first detected in 1801 by C. Hatchett in a specimen of columbite (niobite) from Massachusetts (Phil.

Along CA and DB, on the same side of MN, take MA' = CA, **NB**' = DB; and join A'B'.

SF) The lines MA, **NB**, PC,..

If BN, CP, DQ, FS, GT are the perpen diculars to AE from the angular points, the ordinates **NB**, PC,..

3, if AN and **NB** are regarded as positive, then SF, TG, ET and SA are negative, but the products ET.

Along the base-line, and the lengths and directions of the offsets **NB**, PC, QD,.

Libation bs.t bs bs L vase it, cord on wz wz wz J stick ~J7 basket **nb**.t **nb** r~ looped ?

Taking the case where the motion is strictly in two dimensions, we may write as the polar equation of the surface at time t r =a cos **nB** cos pt, (4) where p is given by p2 = (n3_ n)..

**Nb** Having scattered the Lincolnshire bands, he suddenly turned upon Warwick with his army, and caught him wholly unprepared.