The Pictorial handbook of London : comprising its antiquities, architecture, arts, manufacture, trade, social, literary, and scientific institutions, exhibitions, and galleries of art : together with some account of the principal suburbs and most attractive localities ; illustrated with two hundred and five engravings on wood, by Branston, Jewitt, and others and a new and complete map, engraved by Lowry . lock, rated every day, and kepta few seconds fast. Opposite this, theassistant charged with the duty ofletting fall the ball, stations himselfwith his thumb upon the plate n, andwhen the hand
The Pictorial handbook of London : comprising its antiquities, architecture, arts, manufacture, trade, social, literary, and scientific institutions, exhibitions, and galleries of art : together with some account of the principal suburbs and most attractive localities ; illustrated with two hundred and five engravings on wood, by Branston, Jewitt, and others and a new and complete map, engraved by Lowry . lock, rated every day, and kepta few seconds fast. Opposite this, theassistant charged with the duty ofletting fall the ball, stations himselfwith his thumb upon the plate n, andwhen the hand of the clock has arrivedat the proper second, he presses this plate firmly. By this means the triggerk is released from the notch; the spring g expands and helps the rod in itsdescent; the rods a and b are jerked back in the direction contrary to thearrow point; the piston falls (carrying with it the ball) into an air tube, sodevised as to ease the shock which would otherwise take place, by the com-pressing of the air in it. The violence of the fall is regulated by means of abrass cock near the bottom of the air tube. We will next proceed to the neighbouring building, or the north-eastdome, containing the Shuckburgh equatorial. This excellent specimen ofEamsdens work was presented to the observatory by the executors of SirGeorge Shuckburgh, an eminent astronomer of his day, in 1811, and is elabo-. OBSERVATORIES.—GREENWICH. 647 rately described in the Philosophical Transactions for 1793. It was originallyintended by Mr. Pond to be mounted as an altitude and azimuth instrument inthe south-east dome, but some doubts were entertained of the firmness of thepier, and the idea was abandoned. In this instrument the two pivots of thepolar axis are at its extremities, as also the two pivots of the pivots of the polar axis (9 ft. in length) turn in Ys carried by piers atthe opposite extremities of the dome. The north pivot is at the centre of acircular frame, and t
Size: 1972px × 1267px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1850, bookidpictorialhan, bookyear1854
