1853.] 



WESTRUP'S PATENT CONICAL FLOUR MILL, WITH PLATE. 



245 



them. Althougli, like all other tillnge implements, it works best 

 in dry weather, the digger was used with advantage during the 

 early spring, when it was hardly possible to plough at all; it 

 also clears itself well of any stones which it may pick out of the 

 ground. 



From the description which we have given, it will appear that 

 it is, in fact, a trenching implement, propelled by hoiscs — 

 loosening, and partially bringing the subsoil to the surface, and 

 thorouglily i-educing the whole, like the fork; and not merely 

 cleaving off a slice, and reversing it like the plough : but, as ii 

 only requires four or five horses to work it when set to dig ten 

 inches deep by three feet in width, being equal to four acres 

 dug in a working day of seven hours, in soils where it is rare to 

 see less than three hoi'ses ploughing only one-fourth of that 

 breadlh to a depth of baiely six inches, it is obvious that, apart 

 from the superioi'ity of the result, there is positive economy in 

 the power applied. Circular motion, which general accompanies 

 the application of steam power, will, we trust, in this instance, 

 as in that of the horse power thrashing machine, prove to be 

 only its precursor; meanwhile, it is perhaps quite as well, wilh 

 reference to the speedy and general adoption of this new culti- 

 vating machine, that its introduction is not dependant, in the first 

 instance, upon that of the steam engine. 



In conclusion, we must not omit to notice the application of 

 the "Digger" to works of road formation and excavating generally. 

 It moves as much surface soil in a day as would require forty to 

 sixty men with the spade. 



How tu tell Gold. 



Gold invariahbj exhibits something of the peculiar yellow 

 colour which it is known to possess in a pure state; but this 

 color is modified by various metals with which it may be mixed. 

 Thus it may be described as having various shades of gold- 

 yellow; occasionally approaching silver-white, occasionally resem- 

 bling brass-yellow of every degree of intensity, and even verging 

 on steel-gray in some specmiens from South America. 



The lustre of gold is highly metallic and shining, and owing 

 to the small amount of oxidation at its sui-face, it preserves its 

 shining lustre even after long exposure in contact with other 

 substances, 'i'hus the shining particles are often seen in sand 

 when the quantity is baiely sufiiicient to rejsay the cost of working 

 notwithstanding the \alue of the metal. Even, however, if the 

 Euiface is dull, the true color and appearance is easily restored by 

 rubbing; and when polished it takes a very vivid lustre, which 

 is preserved for a long time in the atmosphere. 



Although in the division which has been introduced into the 

 gold-yellow, brass-yellow and grayish yellow, native gold seems, 

 with some slight modifications, to agree with the geological rela- 

 tions of it's varieties; yet this mode of arrangement deserves 

 little serious notice. The gold-yellow varieties comprise the spe- 

 cimens of the highest gold-yellow colors, though there are some 

 among them which have rather a pale color; they include most 

 of the crystals and of the imitative shapes, in fiict the greatei'part 

 of the species itself. The brass-yellow native gold is confined to 

 some of the regular and imitative shapes of a jjale color, (which 

 is generally called bi'ass-yellow,J and, it is said, has less specific 

 gravity than the preceding one; but this does not seem to ha\e 

 ever been ascertained by direct experiment. The grayish yellow 

 native gold occurs only in those small flat grains which are 

 mixed with the native platiua, and possess a yellow color a little 

 inclining to gray ; they are said to have the greatest specific 

 gravity of them all. The real foundation of this distribution 

 seems to be the opinion, that the first are the purest, the second 



mixed with a little silver, andj,he third \vith platina. It is not 

 known whether the latter admixture really takes jjlace, but it is 

 certain that several varieties of gold-yellow native gold contain 

 an admixture of silver. 



In color and lustre, inexpsrienced persons might mistake various 

 substances for gold ; these are chiefly iron and copper pyrites, 

 but from them it may be readily distinguished, being softer than 

 steel and very malleable; for, although the latter mineral yields 

 easily to the point of a knife, it crumbles when we attempt to 

 cut or hammer it, whereas gold may be separated in thin slices, 

 or beaten out in thin plates by the hammer. There can thus be 

 no possible difficulty in distinguishing these various minerals in a 

 native state, even with nothing but an ordinary steel knife. 

 From any other minerals, as mica, whose presence has also 

 misled some persons, gold is easily known by very simple experi- 

 ments with a pair of scales, or even by careful washing with 

 water, for gold being much heavier than any other substance 

 found with it, (except platina and one cr two exti'craely rare 

 metals,) will always fall first to the bottom, if shaken in water 

 with mud, while mica will geneially be the last material to fall. 

 This is the case however fine or few the particles of either min- 

 eral may be. 



Gold, therefore, can be distinguished by its relative weight or 

 specific gravity, and by its relative hardness, and from other 

 bodies which resemble it. It is described generally as soft, coiri- 

 pletely malleable, and more accurately as softer than iron, cop- 

 per or silver, but harder than tin and lead. It is useful to know 

 facts of this kind, as a simple experiment that can be made 

 with instruments at hand, is often moie \'aluable than a more 

 accurate examination requiring materials not immediately availa- 

 ble. Thus, if It is found that a specimen, (p?rhaps a small scale 

 or spangle,) is readily scratched by silver, copper or iron, and 

 scratches tin and lead, it may, if of the right color, and sinking 

 rapidly in water, be fairly assumed to be gold. 



Westrup's Patent Conical Flour Hill, Avith Plate. 



The great interest which this invention has created in the 

 public mind, and its adoption by various foreign States, including 

 France, Belgium, Austria and Mexico, where mills are already 

 erected, justify us in bestowing upon it a short notice. The bold 

 statement to be proved before Parliament, that by the adoption 

 of this mill, out of the same quantity of wheat consumed in 

 England nearly eighty-two millions of quartern loaves per annum 

 in addition may be furnished to the nation, at a money value of 

 upwards of two millions sterling, is a matter of very great im- 

 portance, exceeding any that can be brought forward by the most 

 expert financier in lessening the national burdens. 



As there is frequently in the most plausible and splendid 

 theories, .some faults or drawbacks in practice, which cannot be 

 immediately detected, we have waited until practical experiments 

 were made before giving our unqualified suppoi't to this inven- 

 tion. There have beeu now several of such experiments, and 

 the conical mill at Wapping has been at work night and day 

 for some months, supplying customere, who increase, as tiia 

 Messi-s. Pavilt publicly state, beyond all their powers of grind- 

 ing ; hence this invention may be said to be already " a great 

 fact." 



The first public experiment was attended by many scientific 

 men, and the reporters of nearly all the daily and weekl}' journals, 

 who, without a single exception, bear witness to the success and 

 the excellence of Mr. Westrup's invention. We shall conclude 



