Carl Czerny 
Complete Theoretical and Practical Piano Forte School [PDF ebook] 
From the First Rudiments of Playing to the Highest and Most Refined State of Cultivation; With the Requisite Numerous Examples, Newly and Expressly Composed for the Occasion

Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. If we now imagine the same passage to be still further lengthened, as in a chromatic run, so that the gradual encrease of tone shall last for 82 notes, for example, We shall’ already employ between 10 and m e different degrees of power.