177) In 1856, _____ discovered a process by which impurities could be removed from iron. This purified refined iron came to be known as ′steel′, which helped in making more accurate tools, implements, weapons and machines.

178) In 1801, _____ invented the first steam locomotive.

179) Who is regarded as ′the father of the railway locomotive′?

180) George Stephenson is regarded as ′the father of the railway locomotive′, because he made great improvements on Trevithick′s locomotive in his _____ in 1814.

181) In 1807, _____ invented the steamboat called the ′Clermont′.