When the revisions of the triennial assessments have been completed, the commissioners, acting as a board of revision, or the board for the assessment and revision of taxes, as the case may be, of the respective counties shall cause accurate transcripts of the assessments to be made out by their clerk, and shall transmit the same to the respective elected or appointed assessors on or before the second Monday of April following, together with a statement of the rate per cent of the tax and the day of appeal fixed by them.
72 P.S. § 5020-507