If by 'main' you mean largest then that would be the boiler.
because the steam is very importance in main engine
Probably the steam engine.
The main difference between a diesel and a steam engine is the diesel engine is an internal combustion and the steam engine is external combustion.
no thomas newcomen did not invent and thing besides a steam engine
there is no such thing as an external combustion engine.. the closest thing to it was the steam engine...
Although it is usually said to be Thomas Newcomen, the history of the steam engine is complicated. Please see the link.
No. Not always (but usually), sometimes the process of discovery can be reversed. The steam engine is one example. The only thing the inventors of the steam engine knew was that steam from boiling water could move the engine.
Before the steam engine, the horse was a big with tranportaion for human whereas, the oxen carried heavy loads such as wood, post e.t.c Horses were still used a lot after the steam engine was invented
answer yes
A steam engine is an external combustion engine. As the steam engine combusts outside of the engine itself.
Usually no, a steam engine usually refers to a system using steam pressure to make pistons in cylinders slide, while a steam turbine refers to a system using steam pressure to make turbine blades spin. However "steam engine" is often used loosely to refer to either.
No, the compound noun "steam engine" is a common noun, a general word for a device used to generate power by the use of steam; a word for any steam engine of any kind.A proper noun is the name or title of a specific person, place, or thing; for example, Steam Engine USA (company) in Providence, RI or "A Short History of the Steam Engine" by Henry Winram Dickinson.