General Notices. 655 



the operator during his future life. Gardeners and others ought to bear 

 this in mind when they send women to hoe turnips, and to other field 

 work. — Co7id. 



Improvements in Wilkie^s Brake . — With regard to the brake, it cer- 

 tainly has a nearer resemblance to Finlayson's harrow than to any other 

 implement of the kind, more particularly in the form of the tines and mode 

 of adjustment. With respect to the tines I do not conceive that I have 

 followed Mr. Finlayson's plan, but rather that of my late father, to whom 

 the merit of originality in this instance unquestionably is due. He first 

 applied the principle of the bent lever to the hoes attached to his drill 

 implements, a perspective drawing of which I furnished for the Farmer's 

 JUagazine for 1821. The drill harrow, with the hoes on the principle alluded 

 to, you have copied into your Encyclopcsdia of Agriculture. The following 

 sketches {fig- 141. a, b, c) will at once show the identity of principle. 



c ifig. 141.) is ,A^ .1 / — ^ h 



that of my father; /— xr/ i /<~?) . ^ " 



A Finlayson's ; and /"x^ Vrf '- ^.^i^^^ 1} // 



B mine. They are _£^j;i:i^^4. c^^-=s^^^^^^^^^b .^i^:^ c 



all bent levers ; '"^*^^^^ 



the fulcrum being at «, the power at i. b I conceive to be stronger 

 than A or c ; the upper curvature at e serving to introduce the prin- 

 ciple of tension ; the power at b acting with greater effect as a coun- 

 terpoise to the resistance at d than in either of the former. The 

 curve erf is that of the cycloid, described by mathematicians as the solid 

 of least resistance : this curve has been considered only as a jeu d" esprit 

 of its great author; but I have found it, from repeated experiment, 

 to answer better than any other. Nor do I think that I have copied 

 Mr. Finlayson in the mode by which the implement is regulated. By 

 an application of the simple, yet beautiful, principle of the parallel 

 movement, 1 have effected, by one instantaneous operation, what, in Fin- 

 layson's harrow and every implement of the kind, required three separate 

 adjustments. In Finlayson's harrow, the lever has only power to lift the 

 fore part out of the ground ; the hind part being raised b)' means of screws 

 at each extremity of the axle ; always a tedious process, and one which can- 

 not be performed while the implement is at work. The tines of Finlayson's 

 harrow are ranged in two parallel rows, at right angles to the line of draught. 

 I have adopted the form of an isosceles triangle, the tines being attached to 

 its equal sides, and by thus having their resisting points obliquely to the line 

 of draught, they act more on the principle of the wedge, and consequently 

 with greater effect and less waste of power. Although, in the first instance, 

 I have fitted up this implement to serve as a brake or harrow, this Is but 

 one of the many uses to which it may be applied in tillage operations. 

 1st, By attaching tines, with triangular feet, it makes a scarifier ; or, in place 

 of tines, one large triangular blade suspended from each of its extremities 

 or angles. Sdl}', By substituting cutting wheels, in place of tines, it is con- 

 verted into a sward-cutter. 3dly. From its extreme accuracy of adjustment, 

 it will make an excellent drill or ribbing machine, and may be made to sow 

 at the same time. And 4th!y, If steam is destined ever to supersede 

 the labour of horses in drawing the plough, this machine, from its peculiar 

 formation, and mode of management, will afford the greatest facility for 

 trying the experiment, as it may be made to take a number of furrows at once. 

 Steam has never yet been applied to tillage, but I am perfectly convinced 

 of its practicability, if the weight of the engine could be reduced so as not 

 to sink in the soil, or consolidate too much the surface on which it moved. 

 I have not yet seen any of the portable steam threshing-machines, but 

 expect to have one fitted up by and by, wiiich may be applied to other im- 

 portant agricultural operations. Mr. Bell's reaping-machine appears to be 

 a nearer approach to perfection than has hitherto been attained, and from 



