Steamships and Steamboats

Side-wheeler steamship
Steamers with a paddle-wheels at each side of the ship and the wheels mounted on the very same shaft. Side-wheelers can carry less cargo than Screw-propelled steamships since there draught will influence on the paddle-wheels efficiency. If the wheels are too much submerged they will not work at all.
Stern-wheeler steamship
Steamers with a paddle-wheel at the stern The Mississippi River Stern-wheelers have a steering system that is very different from other steamships. On a screw propelled steamship, the rudder is behind the propeller. A stern-wheeler has its two very large rudders ahead of the paddle-wheel. This makes these ships more manoeuvrable in astern than ahead going.
Screw-propelled steamship

In the end of 1850 the screw propeller become recognized as superior to the paddle-wheeles and after that the ships began to supersede the sailing ships. Steamers with screw propeller has a number of advantages and these ships are better in rough sea since the screw is continually submerged.
Some people claim that the American Steamship Savannah was the first steamship to cross the Atlantic Ocean in 1819. The Steamship Savannah was on of the sailing ships fitted with steam engine and side-wheels. During her twenty-nine days voyage they used the steam engine less than four days. I don't consider that a steamship voyage. After that voyage the engine was removed and the steamer Savanna continued her days as a sailing ship. Steamship Curaçao a Dutch mail steamer crossed de Atlantic Ocean several times, mostly under steam power, in 1826-28. That I call steamships voyages.

Lots of steamships and steamboats are still sailing. Some of the steamers have got new boilers but most of them uses the engine that have worked since the steamships were launched. The Scotch marin boiler is very common in still sailing steamships.

To distinguish between steamships and steamboats

If a ship's length is 12m or more and her beam is 4m or more then she is a ship otherwise she is a boat. Steamships usually carry prefix before there names:
SS = Steamship,
PS = Paddle Steamship,
TS = Turbine Ship,
SL = Steam Launch,
RMS = Royal Mail Steamship