(1) At the hour fixed for opening the poll the presiding officer and the poll clerk shall, in the presence of the candidates, their agents, and such of the electors as are present, open the ballot box and satisfy themselves and all present that there are no ballot papers or other papers therein, after which the box shall be locked, and the presiding officer shall keep the key; the box shall be placed on a table in full view of all present and shall be maintained there until the close of the poll.