Later they were pulled by steam engine and then combined into a single machine by George Stockton Berry.  Berry took the straw and used it for fuel to heat the boiler.  The header (or cutter) was over forty feet.  This machine could cut and thresh over one hundred acres in a day. (24F)  The cost of the machine was also cheaper than the horse drawn reapers and stationary threshers.  The cost of the reaper and thresher was about $3 a acre while the combine was between $1.50 and $1.75.  

The modern combine has many luxuries.  Most are now equipped with a full stereo system, comfortable seat, and full air conditioning.    The inside of the cab is slightly pressurized so that the air pushes  out of the cab which does not allow dust and dirt to come in.