The road superintendent shall have the custody, care, and control of all the teams, machinery, materials, supplies, and any and all property owned or hired by the district and used in working the road. It shall be his duty to care for and preserve the same, and he and his bondsmen shall be responsible for the proper care and safekeeping of such property and the economical use of the supplies and materials. He shall make a monthly report to the commissioners, which shall be forwarded by them with their recommendations or criticisms to the board of supervisors. Such report shall be a complete inventory of such property, showing the present number, amount, and condition of such property and what was used since his preceding report.