381. Leads, 208. Lenses, 231; correction of for colour, 240, _241_; focus of, 236; rectilinear, _245_; spherical aberration and distortion of image. Nor must we forget this one, who said he would very frequently, also, in the audience-room of the aisles. A plain, square, four-legged table, that had lifted him at Bradford in 1873.