The assessor of St. Louis City shall cause to be prepared plats covering all tracts and lots of land in said city, and the county assessor in every county where the county commission shall have passed an order requiring an alphabetical arrangement of the land list, shall cause to be prepared plats covering all tracts and lots of lands in such county, showing upon the respective pieces of property, as marked down on said plats, the names of the persons to whom each tract or lot was assessed for each year; he shall cause the changes for the assessment of the following years to be marked in different inks, stating on the first leaf of each plat book for what years the different inks were used, and such plats shall not be used to record the changes for a longer period than seven assessment years on each set of plats; and in every such county where an alphabetical arrangement of the land list shall be adopted by order of the county commission, such commission shall allow to the assessor a reasonable compensation for preparing such plat and procuring the books therefor.