Carillon strike the inside of the bells, allowing the performer on the bells, or "carillonneur/carillonist" to vary the intensity of the note according to the force applied to the key. Although unusual, real carillons have occasionally been fitted to theatre organs (instead of the metal bars or chimes more often used in simulation), such as the Christie organ installed at the Regal Cinema, Marble Arch, in London. A carillon-like instrument with fewer than 23 bells is called a chime. The carillon is the second heaviest of all extant musical instruments, only ranking behind the largest pipe organs. The heaviest carillon in
D. H. & A. B. Tower and mill machinery in Holyoke, from Maine to California in the continental United States, and abroad on five continents. While an exact figure is unknown, in a cross-examination of Ashley Tower in a court case between the City of Holyoke and the Holyoke Water Power Company in 1899, Tower stated that of the mills built in Holyoke up until that time, he had been involved in the construction of 25 in some capacity, 16 of which were done in a central design role. While it is unclear from this testimony what share of work was done by each brother and