'Special' rectilinear lens
"Special" rectilinear lens (patent) No. 27900 in rigid setting and set of eight brass lens stops with leather case. Bought for use in Solar Physics Observatory, South Kensington, where it remained until 1912.
"Special" rectilinear lens (patent) No. 27900 in rigid setting and set of eight brass lens stops with leather case. Bought for use in Solar Physics Observatory, South Kensington, where it remained until 1912.