This section is from the book "Bepler's Handy Manual of Knowledge And Useful Infomation", by David Bepler. Also available from Amazon: Bepler's Handy Manual of Knowledge and Useful Information.
In climates having a difference of 70 degrees of temperature between the hot and cold seasons, a railway track of 400 miles is 338 yards longer in Summer than in Winter. Of course, the length of the road remains the same, but expansion forces the lengths of metal closer together, making an aggregate closing up of space between the rails of nearly a yard in each mile.
A steel rail lasts upon the average about eighteen years.