i34 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[ArcrsT, 



freely, but an increase of nearly one-fourth of the power was ob- 

 tained, and the wheel, which still remains as then altered, con- 

 tinues, in all states of the river, to perform its duty satisfacto- 

 rily. 



Tlie amount of power pained, and the beneficial effects pro- 

 duced upon IMr. Brown's wheel, induced a new and still greater 

 improvement in the principle of construction: the first wheel 

 erected on this, which has been called the 'ventilated' principle, 

 was one designed for Mr. Duckworth, at the Ilandfortli Print 

 ^^'(U•ks, near Wilmslow, in Cheshire. This wlieel was started in 

 182^. The improvement of the breast-wheel, with the cliise sole 

 and ventilated buckets, as shown in fig. 5, followed immediately 

 thereon. 



Close-bucketed wheels labour under great difficulties when re- 

 ceiving the water through the same orifice at which the air escapes, 

 and in some wheels the forms and construction of the buckets are 

 such as almost entirely to prevent the entrance of the water, and 

 to deprive tlie wheel of half its power. These defects may be 

 easily accounted for where the water is discharged upon the wheel 

 in a larger section than the opening between the buckets: under 

 such circumstances the air is suddenly condensed, and, re-acting 

 by its elastic force, throws liack the water upon the orifice of the 

 cistern, and thus allows tlie buckets to pass without tlieir being 

 more than half-filled. Several methods have been adopted for 

 relieving them of the air: the most common ))lan is, by cutting 

 hides, as before mentioned, in the sole-plates, close to the back of 

 the buckets, or else making the openings between them much 

 wider, in order to admit the water, and at the same time to allow 

 the air to escape. All these remedies have been more or less effec- 

 tive; but they labour under the objections of a great waste of 

 water and much incon\enience, by the water falling from the open- 

 ings, down upon the lower ]>art of the wheel, e.\clusive of the puff- 

 ing and blowing when the bucket is filling. Otlier remedies have 

 been applied, such as circular tubes and boxes attached to the sole- 

 plates, w liich, extending upwards, furnish openings into the interior 

 of the wheel for the air to escape; but these, like many other 

 plans, have been, to a certain extent, unsucessful, owing to the 

 complexity of their structure, and the inadequate manner in which 

 the objects contemplated were attained. In fact, in wheels of this 

 description it has been found more satisfactory to submit to ac- 

 knowledged defects, than to incur the trouble and inconvenience 

 of partial and imperfect remedies. 



Tn the improvements made by the author, these objections are to 

 a great extent removed, and a thorough system of ventilation has 

 been effectually introduced. Before entering upon the description 

 of this new principle of ventilation, it is necessary to remark, tliat 

 in climates like Great Britain and Ireland, where the atmosphere 

 is charged with moisture for six or seven months in the year, it is 

 no uncommon occurrence for the rivers to be considerably swollen, 

 and the mills depending upon water are either impeded or entirely 

 stopped by back-water; while at other times a deficiency of rain 

 reduces the water-power below what is absolutely required to drive 

 the machinery. On occasions of this kind, much loss and incon- 

 venience is sustained, particularly in mills exclusively dependent 

 upon water as a motive power, and where a number of work-people 

 are employed. 



On the outskirts of the manufacturing districts, where the mills 

 are more or less dependent upon water, these inconveniences are 

 severely felt; and in some situations these interruptions arise as 

 frequently from an excess of water as from a deficiency in the 

 supply. To remedy these evils, reservoirs have been formed, and 

 wheels have been constructed to work in floods; but although much 

 has been accomplished for diminishing these injurious effects, and 

 giving a more regular su]>ply in dry seasons, yet the system is still 

 imperfect, and much has yet to be done before water can be con- 

 sidered equal, as a motive power, to the steam-engine, which is 

 always available where the necessary fuel is at hand. It is there- 

 fore obvious, that any im))rovement in the construction of water- 

 wheels, whereby their forms and requirements may be the better 

 adapted to meet the exigencies of high and low waters, w ill con- 

 tribute much to the efficiency and value of mills situated upon 

 rivers subjected to the changes before alluded to. 



Ventilated Water-Wheels as adapted to Low Falls. 



The first wheel constructed upon the ventilated principle was 

 erected at Ilandforth, in Cheshire, in the summer of 1828; it 

 proved highly satisfactory to the proprietors, Messrs. Duckworth 

 and Co., and gave such important results as to induce its repeti- 

 tion, without variation, in cases where the fall did not exceed the 

 semi-diameter of the wheel. 



In the earlier construction of iron suspension wheels by the late 



Fig. 3. 



Mr. J. C. Hewes, the arms and braces were fixed to the centres by 

 screws and nuts u])on tlieir ends, as shown 

 in fig. 3. The arms c, r ])assed thniugh 

 the rim ft, 6, and the braces e, c, w hicli tra- 

 verse the angle of the rim at /;_/", are, as 

 nearly as ])ossil)le, in the position and form 

 adopted by Mr. Hewes. This arrange- 

 ment, although convenient for tightening 

 up the arms and braces, was liable to 

 many objections, arising from the nuts 

 becoming loose, and the consequent diffi- 

 culty of keeping the wheels true to the 

 circle, and the arms and braces in an uni- 

 form state of tension: gibs and cotters 

 were therefore substituted for the nuts and 

 screws, and since their introduction into 

 the large wheels of the ( atrine M'orks, 

 Ayrshire, the objections have been re- 

 moved, and the arms and braces are now 

 not only perfectly secure, but the peri- 

 phery of the wheel is retained in its true 

 and correct form. It will not, therefore, 

 be necessary further to explain this part 

 of the structure, as the engravings are not 

 sufficiently explicit to give a correct idea 

 of all the parts. 



Having noticed the obstructions offered 

 to the entrance of the water into buckets 

 of the usual form, and the consequent loss 

 which ensues from its retention upon the 

 wheel, after its powers of gravitation have ceased, it may be ne- 

 cessary to show the means whereby those defects were removed, 

 and also to exhibit the relation existing between the breast and 

 the undershot wheels. These terms have, however, become nearly 

 obsolete, as every description of water-wheel may now be properly 

 called a breast-wheel; and in every fall, however low, it is gene- 

 rally found advantageous for the water to act by gravitation, and 

 not by impulse, as during the earlier periods of the industrial ai'ts. 

 If the process of filling and emptying the buckets of the wheels 

 shown in figs. 4 and 5, be traced respectively in each, it will be 

 found, that in the event of a large body of water being discharged 

 into the bucket at D, fig. 4, it could not be filled if the opening at 

 g was closed, and the air was prevented from escaping in that di- 

 rection. Under these circumstances, the air would be compressed 

 and pent up in the bucket, and the water prevented from entering, 

 or be blown out, as already described. Now this is not the case 

 when they are properly ventilated, as a perfectly free passage is 

 constantly open for the escape of the air, in the direction of g, and 

 an equally free entrance is again afforded for the water at D ; the 

 passage for the escape of the air being re- 

 presented by the direction of the arrows 

 through the openings g, g, g, fig. 4, and also 

 the connection of the buckets with each 

 other by rivets and tubular blocks. When 

 a wheel of this descripticui is heavily loaded, 

 a small quantity of water will sometimes 

 escape along with the air, above the lip of 

 the outlet g, into the interior of the wheel; 

 but that is of little consequence, as it is 

 again received into the buckets as it falls 

 upon the wheel; and even this defect may 

 be removed by carrying the edge of the 

 plate higher upon the sole of the upper 

 bucket. For low falls, the length of the 

 tail side of the buckets will, however, be 

 found, in practice, quite sufficient, cither 

 as regards the economy or the distribution of the water. 



Having treated of the entrance of the water into the buckets, it 

 is necessary to describe the facilities afforded by this construction, 

 for its dischai'ge. A quick and easy outlet for the water, when no 

 longer required upon the wheel, is as important as an expeditious 

 inlet; and it is evident that every drop of water which is carried 

 by the wheel beyond the vertical line of the centre, is so much use- 

 less absorption of its power: moreover, in the construction of the 

 bucket for the reception of the water, strict reference should also 

 be had to its free and uninterrupted discharge. Another main 

 point for consideration is the distance to which the water is carried 

 by its momentum, or centrifugal action, when leaving the wheel ; 

 aiid it will be found advantageous to effect the discharge of the 

 water as soon as the bucket passes the lower edge of the stone- 

 breast. This discharge being seldom accomplished in time, in the 



