IS 



Till-: CIVIL ENGIXEER AND ARCHITECT'S JOURNAL. 



[January. 



iiieiit in every brancli of cniistnu'tioii, rniiiisteriiii; to tlio [mblic 

 (■omfort, health, and lite. Our ])a2;es have had their share in these 

 discussions, and we have co-operated with onr pi'ofessioual readers 

 in carrying out a measure ot reform, which is already great. In 

 the ILdhorn and Finsbury and Westminster divisions of sewers 

 .nlone, a reform has been effected, such as has not yet t)een seen in 

 Uiese luatters ; and we are ifi;norant of the .share the medical pro- 

 fession have taken in carryinuf them out. 



Within a period not very distant, the new Sanitary Commis- 

 sioners, or Commissioners of Sewers, will lay down works to the 

 amount of half a million, perhaps a million sterlini;, upon the ad- 

 vice, it is true, of competent professional officers, though under 

 what competent supervision on the part of tlie commission, we are 

 unaware. ^Vhen Mr. Roe proposes his plan for s|iendina; a quarter 

 of a million in getting a new outfall, which of the commissioners 

 will consider it his special dei)artment to examine the estimates, 

 and share in their responsibility ? It will not be Lord Robert 

 Grosvenor — it will not be Mr. Edwin Chadwiok, great as is his 

 capacity as an administrator — it will not be Mr. Richard Lambert 

 Jones, though he is Chairman of the Bridge Committee in the 

 City — it will not be Dr. Southwood Smith or Professor Owen. 

 The two latter will, we apprehend, be of little use in matters like 

 these, and will take no part in them. Thus, a member of parlia- 

 ment, a naturalist, a barrister, an auctioneer, and a physician, are 

 to superintend the disbursement of hundreds of thousands of 

 pounds in public works, and to appoint " well-qualified paid offi- 

 cers" in the engineering and surveying departments; who are to 

 have " a degree of special study which [shall] not only place them 

 beyond the sphere of the discussion of popular administrati\e 

 l)odies, but beyond that of ordinary professional engineering and 

 architectural practice." 



The government have not thought it necessary to give a fair 

 representation to the ])rofession in the new Commission of Sevvers, 

 though the names of Mr. Robert Stephenson, M.P., Mr. Locke, 

 M.P., Mr. George Rennie, Mr. Cubitt, and others, are well enough 

 known at AVhiteball. 



The constitution of the Metropolitan Sanitary Commission is, in 

 reference to the sphere of its future duties, more monstrous than 

 that of the Railway Commission, where three parties, who know 

 nothing of railways — a member of parliament, an East India judge, 

 and an officer in the army — are entrusted to meddle with railway 

 works and administrations. We have so many of these absurd 

 appointments of late, that we have a strong impression that unfit- 

 ness is adopted as the government rule for office, and have some 

 ex])ectation of seeing INIonsieur Jullien prime minister. Why the 

 engineering profession should be exposed to the contumely and 

 neglect from which it suffers at the hands of the government, we 

 do not know ; but the enumeration of the Railway Commission, 

 the Tidal Harbour Commission, and the Metropolitan Sanitary 

 Commission, is a sufficient proof that a degree of unfairness is dis- 

 played, which demands immediate and effective opposition. Al- 

 though the reputation of English engineers is well known to the 

 world — although their professional skill is sought in every country 

 — it may be that they are thouglit by the home government a body 

 too inconsiderable and contemptible to withstand oppression or 

 demand fair play. 



The misconduct of the government on this head has reached that 

 height, that the professions, if they wish to maintain their public 

 character, caimot do otherwise than take instant steps to obtain 

 justice. They have no security at present for the appointment of 

 competent commissioners, or efficient officers, or for the employ- 

 ment of professional men at all ; there is no security that officers 

 of the Royal Engineers, and other branches of the army, will not 

 l>e appointed surveyors of the sevvers and other public works, the 

 present officers being superseded. We think it is the duty of the 

 Institutions of Architects and Civil Engineers to call meetings of 

 their members, to memorialise the government, and send deputa- 

 tions to Whitehall, and take every other necessary step to vindi- 

 cate the rights of their mend)ers. Aggregate meetings of engineers, 

 architects, and surveyors, should be held in the metropolis, and in 

 provinces petitions sent to jjarliament, and memorials to the Trea- 

 sury. 'l"he members of parliament intei'ested in the welfare of the 

 professions, should be requested to take steps in parliament for 

 obtaining ex])laiuitions from the ministers. Mr. Robei't Stephen- 

 son, Mr. Locke, and Mr. Cubitt, would no doubt, on application, 

 give their cordial sui)p(u-t to any necessary measure. 



While we urge tliese strong remarks on the injustice done to 

 engineers by the Metropolitan Sanitary CNminiissioners, it must 

 not be thouglit that we undervalue their Report on the practical 

 points to whi<-h they ajqily tliemselves. We are glad to acknow- 

 ledge it as a step forward in the right way. 



THE FAN BLAST. 



Series of Experimnntx relntive to thr Fan Blant, presented hi/ Mr. 

 Buckle, o/'/Ae Sn/in Worlds, to tlf nnvtiiuj nf the Institute of Mechani- 

 cal Engineers, Birmingham, May 17, and October 21, 18 17. 



(Paper No. 1.) 



The subject of this paper has reference to a portion of a series of 

 experiments on the Fan Blast, — a subject which many members of 

 this Institution are conversant with ; but it is hoped that hints 

 here thrown out maybe serviceable in leading to such constructions 

 of the fan as shall insure the greatest useful effect with the least 

 expenditure of power. The fan has become an indis|)ensable ma- 

 chine in smithies and foundries, it abridges time and labour, and is 

 otherwise a great imjjrovement over the old system of bellows. 

 The uniform stream of the former admits of no comparison, by the 

 puffy blasts of the latter. By means of the fan the smith can heat 

 his work with precision ; he can vary at discretion the size of his 

 nozzle tweyere, without deteriorating the density of his blast. He 

 can conveniently heat one piece of work while sliapiug another. 



In a well-regulated smithy, the main pipe from the fan is fur- 

 nished with an air chest and with nozzle pipes, varying from one 

 to three inches diameter. The pressure of the blast is made to 

 range from four to five ounces per square inch. A nozzle pipe of 

 l| inch diameter is found a suitable size for general engine 

 forcings. ' 



The position of the fan in its chest, or the one preferred and 

 generally made use of, is an eccentric position. The continual in- 

 creasing winding passage between the tips of the vanes and the 

 chest, serves to receive the air from every point of its circumfer- 

 ence, and forms, as it were, a general accumulating stream of air to 

 the exit pipe. The particles of air having passed the inlet opening, 

 and entering on the heel of the blade, would retain the same circu- 

 lar path were it ncjt for the centrifugal force of the air due to its 

 weight and velocity, impelling them forward towards the tips of 

 the vanes; and this continued action is going on, particle following 

 particle, till they are ultimately thrown against the fan chest, and 

 are impelled forward to the exit pipe. It is by this centrifugal 

 action that the air becomes impelled and accumulated into one 

 general stream. But, as will be presently shown, there is a certain 

 velocity of the tips of the fan which best suits this action. 



An ordinary eccentric-placed fan, 4 feet diameter — the blades 10 

 inches wide and It inches longhand making 870 revolutions per 

 nunute, will supply air at a density of 4. ounces per square inch, to 

 40 tweyeres, each being Ig inches diameter, without any falling off 

 in density. The experiments herein detailed were made with a fan 

 3 feet lOfw inches diameter, the width of the vanes being lOf and 

 the length 14 inches; the eccentricity of the fan 1^'^ inches, with 

 reference to the fan case, the number of vanes being 5, and placed 

 at an angle of 6' to the plane of the diameter ; the inlet openings 

 on the side of the fan chest 17i inches diameter, the outlet opening 

 12 inches square ; the space between the tips of the blades and the 

 chest increasing from g inch on the exit pipe to 3^ at the bottom, 

 in a line perpendicular with the centre. To the blast pipe leading 

 to the tweyeres a slide valve was attached, by means of which the 

 area of the discharge was accurately adjusted to suit the required 

 density. 



The guage to indicate the density of the air, was a glass gra- 

 duated tube, primed with water, it being more sensitive and having 

 a greater range than the mercurial one. 



These experiments were made with a view to ascertain what 

 density of air could be obtained, with the vanes moving at given 

 velocities, the outlet pipe being closed, and also at given velocities 

 with the outlet ojien ; but its area varied at discretion. .\nd further, 

 to ascertain the horse-power required to drive the fan under the 

 varied condition. 



The horse-power was ascertained by an indicator, the friction of 

 engine and gearing being deducted in each experiment. M'ith re- 

 ference to the term Tlieoretical Velocity, as used in the table, it 

 may be necessary to observe, that thereby is meant the velocity 

 which a body would acciuire in falling the height of a homogeneous 

 column of air e()uivalent to the re(piired density. Having given 

 the necessary preliminary explanations of the blast above that of 

 the atmosphere, we come to the experiments as recorded in the 

 table, No. 1 a. 



Tiie first colimin is the number of experiments. 



The second is the numlper of revolutions of the fan per niii\ute. 



The third is the velocity of the tips of the vanes in feet per second. 



The fourth is the density of the air in ounces per square inch, as indicated 

 by tlie gauge. 



The fifth is the area of the discharge pipe in inches. 



The sixth is Ihe indicated horse power. 



