MACHINERY OK THE CLAYS. 253 



of field work. The Flail was the first to give way : 

 and by the ingenuity of Menzies, the revolving 

 drum of the Thrashing-machine, beating out the 

 grain by continuous circular motion, was substituted 

 for the alternate strokes of the flail, (just as in 

 navigation, the circular Paddle took place of the 

 back-and-forward action of the Oar,) while the 

 horse-power was concentrated round a pivot, the 

 nearest approach horse-power has made to what we 

 commonly understand by the word Machinery. 

 This point achieved, the introduction of the Steam- 

 engine to that branch of farm operations was at 

 once made easy. The right motion existed before 

 the Steam-engine was brought to bear upon it. 



Once let this be done for clay-soil cultivation : 

 once let all that has been said and written and 

 proved about the properties of such soil, and the 

 properties of the atmosphere, the habits of plants 

 and instincts of roots, condense into an act of mech- 

 anism whose aim and object shall be the most per- 

 fect subdivision that can be effected at a single 

 operation ; and the conquest of the clays is achieved. 

 It will then be seen that none but a PORTABLE power 

 could accomplish it that its practicability lay 

 hidden in the womb of the future, till the Steam- 

 engine appeared, and manual and horse-power were 



