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in reference to the wedge, if put into practice according to the 

 strict letter of the various writers, will, in practice, lead the begin 

 ner into most egregious errors. The wedge has always been 

 considered as a double inclined plane, and its efficiency has been 

 spoken of as being in proportion to the acuteness and length of its 

 sides. Theoretically speaking, this is all correct ; but, in prac 

 tice^ no principle in philosophy proves to be more errone 

 ous than this. Theory would teach the farmer to make 

 his wedges, in order to be most effective when impelled by a 

 given force, sixteen or twenty, or more, feet in length. But 

 practice instructs us that there is a certain length for a wedge, 

 and thickness for the head, which is much more effective, when 

 impelled by a given force, than if it were longer or shorter. 

 Every man who has split much timber knows too well, that a 

 wedge of the proper length and thickness can be driven into a 

 log with less force than one of the same thickness which is twice 

 as long, to say nothing of a short and blunt wedge. Now this 

 is what the beginner wants to know ; he needs something tangi 

 ble some instruction in making wedges that will render his 

 labor as light and effective as possible. Suppose, for instance, 

 an iron wedge is two inches square at the head, and its 

 sides of a true taper to the edge, and twelve or more feet long. 

 Theory would instruct us, that a wedge of such dimensions could 

 be driven with less force than one about ten inches long, of a 

 true taper to the edge, with the head of the size already men 

 tioned. But, in practice, we find that such a long wedge would 

 be utterly useless, because it would not possess sufficient strength 

 to resist the force of heavy blows without being crushed or 

 doubled up in places, and it would be very liable to twist 

 and turn wherever the grain of the timber ran ; and, more 

 than all else beside, it would require three times as many blows 

 to drive it up to the head at it would require to drive a wedge 

 of the proper dimensions, and the friction would be so incal 

 culably great in such a long wedge, that it is not at all proba 

 ble that the force exerted by one man with a beetle would be 

 sufficient to drive such a wedge clear to the head, even were it 



