Bras footwarmer from the GWR royal saloon, used from c 1860-1901.
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Early carriages were cold and draughty, making footwarmers esential for comfort. However, this type of footwarmer was filled with hot water and would only remain warm for a few hours. Later versions were made which used acetate of soda crystals to create a chemical reaction. The resulting heat would last for up to 60 hours.