From the 1941 era Massey Harris 21 to the Massey Ferguson 29 of 1984, combine harvesters changed almost beyond recognition, and this programme shows these developments by looking in detail at 22 key models at work Although the layout was primarily conventional, there were wider auger-fed headers, multiple threshing drum set-ups and larger straw walkers and sieves. Grain tanks had higher capacity, bagger models disappeared and driver comfort was transformed. There was also a lot more horsepower.