In order to enable the legislature hereafter to make specific appropriations for the expenses of the government, it shall be the duty of the secretary of the commonwealth, and superintendent of common schools, auditor general, state treasurer, surveyor general and canal commissioners, severally, to communicate to the legislature, on or before the third Tuesday of January in each and every year hereafter, a detailed estimate of the contingent expenses of their several departments, for one year from the first day of June then next succeeding.
72 P.S. § 3421