Before electricity, light was tricky business. Flames cast ltmtted light, are vulnerable to winds and weather, and can lead to disaster. Making fire portable and dependable was so difficult that lights on moving vehi cles were hardly ever considered. The early trains traveled1 only during the day. The tracks were too dan gerous during the dark of night, and passengers wanted to see where they were traveling anyway. In the late 1830s, railroad traffic became heavy enough for freight trains to delay passenger trains. To avoid these delays, railroads started running freight trains at night. Horatio Allen's 183 1 innovation, the '!rack Illuminator," was suddenly in demand. It was a pile of pine knots burning in an iron grate that sat in a box of sand on a platform car. The car was pushed ahead of the locomotive. The illu minator did not cast much light. but it warned of the approaching train and was the best technology available.
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