Windmills, used for pumping water, were popular on Vermont farms by the 1880s. The tall, narrow towers seen in Vermont were invented by Daniel Halladay, of Connecticut, in 1854. Halladay moved to Illinois and founded the U.S. Wind Engine & Pump Company, which soon became the largest manufacturer of windmills in America. Halladay developed the tail, which allowed the windmill to automatically change direction with the wind. Not only did this allow for a more efficient use of the wind power, but it spared the windmill from destruction during heavy wind storms. The tail, seen in the image below, protrudes off the back of the fan. As the wind hits the tail, the fan turns into the wind.
The earliest Halladay windmills were constructed of wood. The blades on the fan were wider and not as strong. The advertisement for the U.S. Wind Energy & Pump Company, seen below, illustrates the wooden windmills. Also note the thick wooden frame of the windmill in the image on the right.
Steel fan blades, which were thinner and more durable, were developed in 1870. The older wooden windmills lacked the pumping capacity of the steel windmills, and companies soon stopped manufacturing the wooden mills. The U.S. Wind Energy & Pump Company could not keep up with the new steel technology and soon closed their doors. Aerometer picked up where they left off and soon became one of the largest manufacturers of steel windmills. Steel windmills were lighter and taller and less prone to destruction during a storm. Note the tall, slender frames in the images below.