; the sign for their firm can be seen between the 2nd and 3rd floors. David Tower, the senior partner of the firm, first entered the business of engineering paper mills as an apprentice
millwright in 1845 at the age of 13, and eventually moved his own practice to Holyoke in 1867. The brothers would also play a significant role in establishing the economic success of the
Kimberly-Clark company, designing one of its earliest groundwood pulp plants in
Kimberly, Wisconsin in 1888. More significantly however, their designs for
sulfite pulp mills in
Appleton, Wisconsin built in 1890 gave the company a significant advantage. With this new plant the company had the resources and geographic scale of the American Midwest, while operating the first such mill west of Pennsylvania to adopt the improved process which derived almost pure
cellulose from wood pulp. At the beginning of their partnership the firm was located in the Hadley Falls Bank Building which sat at the corner of Main and Dwight (not to be confused with the later Hadley Falls Trust Building at the corner of Maple & Suffolk), and subsequently relocated to Holyoke's Flatiron block, which was said to have had advantageous lighting at most hours of the day due to its rounded northeast-facing corner, which had windows facing in three different directions. Originally Ashley B. Tower joined David H. as an apprentice, with no prior experience in engineering work or architecture besides a previous carpentry apprenticeship. at
Salto, São Paulo, the site where a large paper industry was begun through the mill designs of the brothers. One of the things that reportedly made their firm successful was their study of foreign as well as domestic designs, with reports that the Towers went abroad to Europe in 1884–1885 to examine the latest designs in paper mills on that continent. Designed by the brothers Tower, it became the first industrial paper mill in South America and remains a functional site even today, producing large quantities of paper for currency. Another example of the brothers' methodical research can be found in the construction of the, since demolished, Hampden County Jail. When first contracted for the design, the two not only consulted with county authorities through their several drafts of the facility's design, but personally travelled through a number of states to obtain the best working ideas for penitentiaries at that time.
Legacy In their time the two were "widely regarded as the best paper mill architects in the world", attributed to the fact that the brothers employed both civil and mechanical engineering and made thorough study of sites to employ natural power in their architectural plans. Upon their deaths, the two brothers were praised like royalty, with Ashley Tower, described in one trade journal as "the
Nestor of paper and pulp mill engineering" and David Tower touted by
William Randolph Hearst's national news service as "the Paper King". During the firm's time under the handle "D. H. & A. B. Tower", the two designed at least 100 or so mills, So prominent became his work that he would later be described in a 1908 Congressional hearing on the industry as "the famous paper and pulp mill architect of the East". Another noteworthy pupil of the brothers was Hardy S. Ferguson, who went on to build the
Great Northern Paper Company's mills. The company's facilities, which remained operational into the 21st century, were his first independent project in 1899. He became another mill engineer subsequently who, in his own right, would influence mill engineering on an international scale as, at the time of its construction, the Great Northern Paper Mill was the world's largest. Two alumni of the firm would go on to work as chief engineers of the
Niagara Falls Hydraulic Power and Manufacturing Company, including Arthur W. French, who subsequently became a professor of engineering at the
Worcester Polytechnic Institute, and Daniel P. Jones, who was tasked with not only its management but the expansion of its facilities. Joseph Wallace, the biographer and evangelist of the brothers' work long after their deaths, He became Ashley Tower's last junior partner in 1897, leaving shortly before Tower's death, and would go on to develop his own successful millwright business, one of his own major accomplishments being the design of hydraulic plants for Kimberly Clark. ==David H. Tower==