"I did not intend to make the present Tables of Income Consolidations for Arithmetic Practitioners, but rather for those who, either due to lack of time or competent talent... will not have bothered to learn it (...). These Contifacts are very useful, and convenient, as they can be applied to many cases. and they offer work already done... for anyone who has given or received money in wealth, for employment, and in any another way, that money can be given or received as income, as well as for the interests of the Mountains, of the Doti, for the rental of the Houses, of the Lands, and Furniture, and also for the salaries of the Garzoni.. ." (Introduction, p.III).