1843.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL 



427 



both in Germany and in England, seemed to have been directed to the sub- 

 ject simultaneously, without any correspondence between the engineers of 

 the two countries. There had been many competitors for the premiums of- 

 fered in Cornwall for the best method, but the only successful plans were 

 those mentioned in the paper; and the machine therein described was a 

 combination of the plan proposed by Mr. Loam and that actually in use in 

 the llarlz mines. 



Mr. Buddie recollected many years ago seeing a model of a somewhat 

 similar machine, which had been in use in Germany for fifty years: it con- 

 sisted of two rods, upon whose sides were hooks, at given distances, which 

 on receiving a reciprocating motion were alternately engaged on the oppo- 

 site handles of the "kibble" containing the ore, which was thus raised to 

 the surface ; it was prohable that the idea of raising the miners had been 

 taken from this old machine. 



Mr. Taylor replied that he did not think Mr. Loam knew of the existence 

 of any machine of the kind, and that the first impulse given to the subject 

 was by the premiums offered for the best method, which had directed the 

 attention of engineers to it. An American machine somewhat similar to 

 that described by Mr. Buddie had been exhibited in London by Mr. Slade ; it 

 was designed for raising ore and water, but Mr. Taylor thought it applicable 

 to raising the miners, and directed the attention of the patentee to the sub- 

 ject, but the machine was not successful. 



In answer to a question from the President, Mr. Buddie said that the 

 system was not applicable to the mines at Newcastle, as the men went up 

 and down by the rope. By the use of guides and slides, the rate of drawing 

 the coal to the surface was generally about 18 feet per second, which was 

 not, however, considered sufficient, and a greater velocity was contemplated. 



" Description of Annular Valves used for Pumps for Water-works, Sfc." 

 By Richard Hosking. 



The annular valve consists of three concentric rings, arranged pyramidally, 

 and resting one upon the other, thereby affording a free passage for the 

 water around the circumference ; the upper ring is attached to a stalk, and 

 the two lower ones have internal wings, which serve as guides when the 

 rings are in motion. 



The chief advantages afforded by these valves are stated to be an increase 

 of water-way and a reduction of concussion, for as the concussion occa- 

 sioned by the shutting of pump-valves is in proportion to the surface in 

 contact, and the square of the height or distance passed through while in 

 the act of shutting, the greater the number of parts of which the valve is 

 composed, the greater will be the freedom of water-way, and consequently 

 the burthen on the engine and the concussion will be proportionally dimi- 

 nished. 



These valves were first used in two 30-inch pumps at the Waldersea 

 Drainage, near Wisheach, and they have since been introduced into the 

 Royal Polborro Consols Mine and the Vauxhall Water-works. 



The description is illustrated by a drawing, showing the construction of 

 the internal parts. 



" On the construction of Valves used in Pumps for raising Water." By 

 Samuel Collelt Homersham, Assoc. Inst. C. E. 



The author first describes the original leather flap valves which are in 

 common use, shows their defects, the modifications which have been intro- 

 duced in them, and the reasons why a better kind of valve was necessary, 

 particularly for large pumps appended to steam engines, quoting from Mr. 

 Wicksteed's work on the Cornish engine, x that by the closing of the valves 

 at the East London Water-works, the whole of the engine-house was shaken. 

 This led to the application, by Messrs. Harvey and West, of a modification 

 of the double-beat steam valve, 2 only making it self-acting; by this, it is 

 stated, the concussion is so much reduced that little inconvenience is felt 

 from it. No air is required to be admitted beneath, as is frequently the case 

 with common valves, consequently the pump when at work lifts its full com- 

 plement of water. 



The author states that in this valve the diameter of the top seating is 

 somewhat smaller than the lower, for the purpose of allowing a sufficient 

 area for the pressure of the water to act against in lifting it. He remarks 

 that the pressure required to open these valves appears to vary from 2 lb. to 

 51b. per square inch, and that it does not seem to follow any uniform rule. 

 The seatings which answer best are composed of pieces of wood fitted in a 

 groove with the fibres in a vertical position. The principal advantages of 

 this kind of valve, as to durability, slight concussion on closing, facility of 

 repair, &c, are then enumerated ; hut it is urged against them that the pas- 

 sage for the water is circuitous, and therefore the power required to force 

 the water through, is cousiderahle, and that in a large valve the height to 

 which it rises is too great. 



He then states that Mr. James Simpson, who has had great experience in 

 the difficulties attendant upon the use of large pumps, some years since con- 

 ceived the idea of obtaining valve openings nearly equal to the full area of 

 the clack chambers, by means of a conical valve formed of rings shutting 



1 " An Experimental Inquiry concerning the Cornish and Boul on & 

 Watt Pumping Engines," by Thomas Wicksieed. Weale, London, 1841. 

 3 See drawing ana description of these valves in the Journal, Vol. Ill, p. 41. 



down upon each other; this was afterwards modified into a valve with sepa- 

 rate seatings for the rings to fall upon, allowing a passage for the water both 

 inside and outside the rings, thus obviating the necessity of their lifting 

 more than one-half the space of the width of the openings in the seating, 

 and it was found that in valves of large diameter, by increasing the number 

 of openings, the height of lifting in opening could be further reduced ; the 

 closing was necessarily more rapid, the concussion was nearly avoided, and 

 the passage of the water was rendered direct and free from bends and inter- 

 ruptions. A valve on this construction was adapted to the engine at the 

 Lambeth Water-works, and it was found on setting it to work, that a coun- 

 terbalance weight of upwards of one ton, required to be moved from the 

 pump side of the beam, to some distance on the steam piston side; the 

 saving of steam consequent on this and the action of the valve, amounted 

 to about seven per cent, of the quantity previously used. The same effect 

 was observed at the Chelsea Water-works, where similar valves were substi- 

 tuted for those of Messrs. Harvey and West. 



It is stated that in consequence of the galvanic action between the brass 

 rings and the iron seatings, wood seatings were adopted, and have been 

 found very preferable. The dimensions of all these valves are given in de- 

 tail, and also of several other large valves which have been made. 



The question of the proper weight of valves in proportion to the height 

 of the column is then examined at great length, and the following rule is 

 given : " The mean velocity of the water in feet per second through the 

 valve, being ascertained, one-half more is added to this velocity and consi- 

 dered as the maximum velocity of the water through the valve ; and the 

 height of the head of water being found that would produce this velocity, 

 every If inch of such height is considered equal to one ounce weight avoir- 

 dupois, acting upon each square inch of the area of the valve, against which 

 the water impinges, in its passage to the pump barrel, allowance being made 

 for the difference of the weight of the ring, when immersed in water, com- 

 pared with its weight in the air." By this rule, it was found that a consider- 

 able weight required to he added to the valves which had been erected, and 

 that addition rendered the concussion scarcely perceptible. 



The author advocates a large area in the valve passages for the water to 

 flow through, in order that the power of the engine may not be expended 

 inputting the fluid in motion to fill the pump- barrel. He states that the 

 proper area, depends on the diameter of the pump and the working velocity 

 of the plunger ; and that if the maximum velocity of the water up the 

 suction pipe, is not allowed to exceed 6 feet per second, but little advantage 

 will in ordinary cases be gained by reducing that velocity ; that an increase 

 of speed is often unavoidable, but that it causes a great expenditure of 

 power ; and he quotes Mr. Wicksteed's experiments in support of this po- 

 sition. He urges from this, the importance of reducing the velocity of the 

 water in entering and in quitting the pump barrel ; and also that the lift of 

 the valve should not exceed 2 inches, and should be as much less as possible, 

 as the valve in that case closes quickly before the return stroke of the en- 

 gine commences. Short lifts are then examined, and it is stated that the 

 valves will not close rapidly, unless they are weighted sufficiently to resist 

 the maximum velocity of the water flowing through them and are carefully 

 adjusted to it ; and that if they are too heavy there is a loss of power in 

 working the pumps. 



Several modifications of these valves, adapted to various uses, are then 

 described, and the author states that his intention is, to lay before the Insti- 

 tution, an account of such valves as had been found to answer well in prac- 

 tice; and to direct attention to the correct principles for constructing them 

 of proper proportions and of durable materials. 



The paper is illustrated by eight detailed drawings of different construc- 

 tions of valves, and by three models of some which have been in use and 

 are found successful. 



Remarks. — Mr. Simpson corroborated the account of the advantages of 

 the valves described in the paper ; he bad found them practically useful and 

 economical. 



Mr. Wicksteed said that with Messrs. Harvey and West's improvements, a 

 valve 4 feet in diameter which formerly rose between 4 inches and 5 inches, 

 now only lifted If inch ; the concussion was diminished and the durability 

 insured; the latter was increased by substituting wooden faces for metal 

 ones; by this means also the corrosion, attendant upon the contact of two 

 metals, was avoided. One of these valves had already lasted three years, 

 and was still quite good. The principal improvement consisted in making 

 the water pass all round the circumference, instead of through the centre of 

 the valve. The difficulties which had been experienced at Old Ford had not 

 arisen from the form of the valves, 3 but from the situation in which they 

 were placed ; he argued, therefore, that when experiments were made upon 

 these valves, new boxes and suction pipes should he made expressly for them, 

 and they ought not to be adapted to the pipes from whence the old shaped 

 valves had been taken. He approved particularly of the form of the double- 

 btat valves as possessing great strength, and reducing the liability to frac- 

 ture. 



Mr. Tavlor said, that the meeting was much indebted to the author, for 

 laying down positive rules and principles, on a subject which had not hitherto 



3 We rather suspect that Mr. Wicksteed must have been misunderstood in 

 bis remarks, for we understood that be alluded to the use ot two valves,«and 

 that he said the lower valve rose 4 or 5 inches, while the upper one rose from 

 1} in. to 1 1 in. only.— [Ed. C. E. & A. Journal.] 



