§ 40. Regulations of duties of officers. The common council may, by
ordinance passed by three-fourths of all its members, not inconsistent
with this chapter, or other laws of the state, regulate the powers and
duties of any city officer or department; and it has power to
investigate all city officers and departments and shall have access to
all records and papers kept by every city officer or department, and has
power to compel the attendance of witnesses and the production of books,
papers or other evidence at any meeting of the common council or of any
committee thereof, and for that purpose may issue subpoenas signed by
the president.