Thursday’s article noted the famous “Year Without a Summer” that occurred in 1816, the result of the eruption of Mount Tambora.  The volcano discharged dust and sulfurous gases that spread around the globe.  The diary of Hiram Harwood of Bennington, Vermont, noted that on June 11, 1817, frigid temperatures found New Englanders building “roaring fires in their hearth, as killing frosts turned leaves and gardens black.”  Once the cold spell ended, the farmers replanted their crops only to have temperatures plummeting again in July.  On August 21, hard frosts killed crops in Boston and a snowstorm whitened the peaks of the Green Mountains. The eruption inflicted climatic changes all over the Northern Hemisphere and is one of the first examples of global cooling. If you're visiting from other parts of the country, sometimes it's hotter and steamier than this. Years ago, the hum of the air-conditioner was found in locations such as stores, offices and bars. Now, air conditioning provides comfort in the car, bus, train, jet, with numerous units for the house and office. How did they keep cool, in south Louisiana 50 years ago? By moving air and ventilation, courtesy of the electric fan. In many older homes in our area, a 4-by-4 fan - in the attic - created comfort, and it did it solely on the principle of circulation. With the screened windows open, a persistent draft of air would flow from room to room. The ceiling fan also enhanced the movement of air. By recirculating the rising heat, this simple, time-tested device provided a downdraft of comfortable air to individual rooms.