Considerable objection was made to the sharp whistle of the Rockford Silver Plate Co. by the business houses in the locality. The company have replaced it with a new chime, presented them by the Erie Iron Works. The new whistle is immense, being 15 inches in diameter and 38 inches long. The peculiar merit consists in producing three distinct tones pitched to the first, third and fifth of the common musical scale, making a very agreeable musical chord. When applied at full force it can be heard 20 miles.
Source: The Jewelers' Circular and Horological Review - 25th April 1894