MGTutoring.com. A Rational Perspective on Education.

This brief account of the history of AC in Texas illustrates the development and integration of knowledge, and that physical science is not –as most think — some bauble of the intellect, something separate from everyday life, but is rather certain, proven, reasoned knowledge of reality, of things we find and have to deal with on an everyday basis.

It is fascinating to read how technology of a time reflected and was limited by the science of the time, and how technology develops as physical science — reasoned knowledge of the cause-effect relationships amongst and the identity of physical objects — develops.

In “How Early Texans Beat the Heat” (Monday, August 3, 2009), U.S. Sen. John Cornyn writes:

Early Texans also used well water to cool their homes. They pumped water from the well to fan radiators, which were installed in spaces they wanted to keep cool. The practice of using well water as a coolant proved costly and not entirely effective. Unless homeowners used the water for other purposes after they cooled their homes, it was an expensive effort that didn’t yield significant results, with the well water usually only reaching 62 to 72 degrees

In the 1800s, German dairy farmers in central Texas began practicing evaporative cooling as a means of keeping their dairy products cool. The system involved placing the evening milk in metal cans, covering those cans with wetted blankets, and using fans to blow air through the blankets. This typically cooled the milk to 70 or 75 degrees, and the practice was eventually modified and used to cool homes.

Soon Texans were able to purchase natural ice from northern states that was cut from frozen lakes and rivers and shipped to Texas. When this supply was cut off during the Civil War, Texans used their ingenuity and resourcefulness to produce ice mechanically. In 1865, Daniel Livingston Holden of San Antonio installed a Carre absorption machine, which had been shipped from France to Mexico, and eventually made its way to Texas. Holden made several improvements to the machine, which previously used a combination of ammonia and water as a refrigerant. Holden fastened steam coils to the machine and used distilled water to make clear ice. His practice became popular and by 1867, three companies in San Antonio were manufacturing artificial ice.

As early as 1870, Texas cities began manufacturing cooling devices, which opened the door to a new industry in Texas. Manufacturers developed creative ways to use ice, as it became more readily available, combined with fans and air ducts. By placing a 300-pound block of ice in a vault, and then using a fan to blow air through the vault and into an outlet duct, cool air was emitted into a room or space that needed cooling. By 1920, Texans placed large blocks of ice in enclosed pools. From there, the ice water circulated to fan radiators that then cooled rooms, restaurants and other spaces. For many years, this process kept churchgoers cool at the First Baptist churches of Dallas and Austin, along with Highland Park United Methodist Church in Dallas.

Rice Hotel cafeteria became the first refrigerated air-cooled building in the Houston area in 1922. San Antonio was home to the Milam building-the first air-conditioned high-rise office building in the country in 1928.

Source: Texas State Historical Association’s Handbook of Texas Online.

In”Single molecule, one million times smaller than a grain of sand, pictured for first time” (7:39 PM, 28th August 2009), Claire Bates
 writes:

It may look like a piece of honeycomb, but this lattice-shaped image is the first ever close-up view of a single molecule.

Scientists from IBM used an atomic force microscope (AFM) to reveal the chemical bonds within a molecule.

‘This is the first time that all the atoms in a molecule have been imaged,’ lead researcher Leo Gross said.

Published by Associated Newspapers Ltd
Part of the Daily Mail, The Mail on Sunday & Metro Media Group

© 2009 Associated Newspapers Ltd

Amazing. Check out the picture they have!!