Section 123. Secretary of the board; commissioner of supplies

The board of
  contract and supply shall appoint a secretary to hold office during  its
  pleasure,  whose  duty  it  shall  be  to keep a full journal of all the
  proceedings of the board and to perform such additional duties as may be
  required by the board, or by law or ordinance  of  the  common  council.
  Where any work or repairs needed to be done, or materials or supplies to
  be furnished for any office, court, board or department shall not exceed
  two  hundred and fifty dollars in cost, the board of contract and supply
  may by general or special rule  authorize  the  commissioner  of  public
  works,  or  the  commissioner  of public safety, or the secretary of the
  board, or any of them, to give written orders therefor and purchase  the
  same.  No  materials or supplies shall be purchased for, or delivered by
  or upon the order of the commissioner to any officer, board, court, body
  or department of the city, except upon the requisition in  writing  from
  the  officer,  board,  body or head of the department for which the same
  are required. The commissioner shall require a receipt in  writing  from
  each  officer,  board,  body  or head of the department for all supplies
  delivered to him or it by the commissioner or on his order, and he shall
  approve, in writing, all claims  for  any  such  materials  or  supplies
  purchased  by him, before the same shall be presented to the comptroller
  for audit.