>Determined to pursue the idea further, Craven contacted Dunnett’s widow and purchased the man’s patent for a sum of less than £20 (about $30 USD). This is sli

>Determined to pursue the idea further, Craven contacted Dunnett’s widow and purchased the man’s patent for a sum of less than £20 (about $30 USD). This is slightly misleading. If that was the actual price he paid, it was the equivalent of about £500 today.