The border shows two of his inventions : the thermosiphon ( the founder of the central heating systems ) and a calculating machine and which was admired by his contemporary Charles Babbage .
A calculating machine is a forerunner of the modern computer .
The border shows two of his inventions : the thermosiphon ( the founder of the central heating systems ) and a calculating machine , a forerunner of the modern computer , and which was admired by his contemporary Charles Babbage .