Large Main Jigger With Case, by Marconi Company, London, Early 20th Century

Large Main Jigger with mahogany? case mounted upon large base, all attached to larger base with lacquered brass nuts and parallel brass sliders. Object can slide along larger base with nuts are untightened. With eight terminals, consisting of small ebonite bases with bras tubes, in horse-shoe formation mounted upon upper surface of case. With connector wire, consisting of insulated cable with light-coloured wooden handles at both ends, attached by one end to one of aforementioned terminals. Also including ebonite terminal with brass nut mounted vertically upon one shorter side of large base. Interior of case not visible.