January 12, 1917. THE COLLIERY GUARDIAN. 73 definite information as to its original position, although it was moved from Oakerthorpe in or about the year 1841 to its present site, where it has been in continual use draining water from the outcrops of the Deep Hard and Deep Soft (Derbyshire) seams. The first boilers used in connection with the atmospheric engine were generally constructed of copper or wrought iron,, and had a dome of lead or even of timber. In an attempt to economise heat from smelting furnaces, a . few boilers in Cornwall were actually built in granite, with copper heating tubes passing horizontally through them. In their earlier models, both Newcomen and Smeaton placed the boiler imme- diately under the cylinder, this practice being in vogue, at any rate, until about 1772. After that date, boilers and engines were usually fixed in separate buildings. The former were then of the “ beehive ” type, heated on their under sides, which were convex, with circular flues, spiralling out- wards. A boiler of this type was at one time connected to Thompson’s engine. For many years the engine appears to have worked on exhaust steam from the fan. This was fed into the present boiler at about 31b., thence into the receiver above and on to the cylinder. The pressure in the receiver varied between 2 and 31b., in synchronism with 'the strokes of the engine. The fan, however, was recently electrified, and steam had to be generated in the boiler at a pressure of 5 lb., the steam supply pipe being simultaneously reduced from a diameter of 10 to 5 in. The iron cylinder, which is 11 ft. long by about 1J in. thick, has an inside diameter of 4 ft. 9} in., and is fixed to a foundation of yellow sandstone, one of the retaining bolts being clearly visible. This cylinder casting is a remarkable piece of work, considering the time when it was made. Its weight cannot be less than 4| to 5 tons. The sniffing valve (so called from the peculiar noise it made), by which air entering with the injection water is expelled from the cylinder, is fixed on the top of the eduction pipe just behind the door post. It takes the form of a 2 in. mushroom drop valve. The method of control, presuming the piston to be at the bottom of the cylinder, is as follows :—When starting the engine, a hand lever, previously held up by a prop in a position closing the steam valve by means of the connecting rod, is released, which allows a tumbling weight to fall down, thus opening the steam valve. The steam admitted to the cylinder blows out any water remaining from previous condensations, and also (through the sniffing valve) any air that may have accumulated. As the piston reaches the top of its stroke, a bobbin or tappet (on a plug rod) comes into contact with a lever, which it raises until the tumbling weight lever falls over to a position of rest on the other side of the rocking shaft, and the steam valve is closed. At the same time, through another lever, a catch, and the rocking shafts to which they are attached, the injection valve is opened by means of a connecting rod. The water then injected into the cylinder produces a vacuum, by which the piston makes the downward stroke. Towards the end of this stroke, two blocks reverse the movements of the steam and injection valve mechanisms respectively, and the cycle of operations is complete. It is, of course, essential that the steam pressure should always be above that of the atmo- sphere, or the discharge of the condensing water and air might fail, and stop the engine. To the “ plug rod,” “ plug tree,” or “ plug frame,” as the vertical beam is variously called, a particular interest attaches, in, that the original operation of the valves in New- comen’s design was alleged to have been manual, and only to have bcome automatic after the erection of his Wolver- hampton engine. A thick vertical rod close to the plug beam works the “ Jack-head ” pump, by which the condensing water is forced into the cistern on the top storey, a large pipe not only feeding this cistern, but, by reason of its height, also supplying the necessary head or downward pressure for the injection. The spray itself is fed by an L-bend under the middle of the cylinder, ending in an automatic carrot valve. The quantity of water injected per stoke would appear to be about 6 gals. The first storey of the engine house contains the cylinder top and the chain connections between the piston and the quadrant. To these chains are lashed large lumps of pig iron as counter-weights to help the vacuum. The piston works at a speed of six throws per minute. The length of stroke used to be 7 ft., but of recent years this has been reduced to 6 ft. It is. not possible to tell. whether the cylinder was properly bored, but the probability is that jt was, John Wilkinson having discovered a satisfactory rigid method in qr about 1774. The name of the maker is cast on to a V-groove at the top of the cylinder on the side next the wall. An interesting device, introduced by Beighton, consists of a pump which raises water from the hot well to a height just sufficient to overcome the pressure in the boiler, with which it is connected by a vertical wall pipe. The pump rods, braced together at the surface, are divided into three, separate units in the shaft. The water is raised from a depth of 120 yds. in three lifts of 40, 30, and 50 yds. respectively, by means of single-acting pumps 12J in. in diameter, the quantity of water dealt with being about 27f gals, per stroke.- It would appear that 166 gals, of water were raised 360 ft. per minute. The work done, there- fore, would be 166*5 gals, x 101b. x 360 ft. = 599,400 ft. lb. per minute, or 18-1 horse power. As the cylinders are 57| jn. in diameter (equal in area to 2,597 sq. in.), with an effective stroke of 36 ft. per minute, they would require an average working pressure of 6-2 lb. per sq. in. to do this work. In addition to lifting the water, the engine had to lift the unbalanced weight of the pump rods and overcome the fric- tional resistance of itself and the pumps. It is therefore probable that, with the imperfect vacuum obtainable under the conditions mentioned above, there would not be any large surplus of power available. It. is evident that at some time the additional balance weights added to the piston have been .applied for the purpose of easing the engine. In this connection, it1 should be mentioned that the unbalanced weight of the pump rods usually effects the suction stroke. The pressure in the boiler, though nomi- nally 31b. per sq. in., was not expected to do any other work than cover condensation losses on filling the cylinder, which was always cold from the injection of the condensing water. DISCUSSION. The President moved a vote of thanks to Mr. Anderson for his paper, which, he said, was of great historical value.t It was to be hoped, as the author suggested, that the engine in question would be pre- served, but, failing that, Mr. Anderson had done the society a valuable service by • placing the photographs and particulars on record. Not many members of the society had had the opportunity of seeing an atmo- spheric engine of the type described. He remembered one at a colliery in North-East Derbyshire which was working up to 25 years iago, but he could not say whether it was in existence at the present time. In that case the beam was omitted. It was an engine of the bull type, the cylinder being placed over' the shaft, and the piston rod directly connected with the pump rods. The upper part of the cylinder was open, so that the piston could be seen rising and falling. There was no doubt that an engine of that description did valuable work. Mr. Phelps showed on the screen two photographs of the heading of a shaft at Walkden, Lancashire, and an engine, but not being an engineer, he was unable to say what the age was. The engine- was immediately over the tunnel of the. Bridgewater Canal, down which the coal was brought in boats from the underground work- ings. It might be of interest to know that the Duke of Bridgewater had a steamboat made, the engine of which he believed was on the Newcomen principle. It was in use for a certain length of time, but the old Duke found that it tore up the banks of the canal, and had it removed. The boat was rather broad in beam, and in the bow was a beehive type of engine set in brickwork, with a fire hole underneath. Several pipes led from the top of the beehive boiler to the engine, which was amid- ships. There did not appear to be a crank in the engine, but the paddle wheel at the stem was worked by a bevel gearing, which was an interesting point. The engine was taken out and used at Worsley or Walkden, and was eventually broken up. One or two of the parts-, however, were , still in existence at the Walkden yard,, and perhaps something could be done to preserve them. Judging from-the character of the piston valve, it must have been a Newcomen engine, because instead of the piston rod, it had a sort of shackle at the top, which would be for attachment to an arrangement such as Mr. Anderson had described. In one of the illustrations put upon the screen, he noticed that -the piston cylinder had not a top to it, but there was a shackle attached to the valve. Aid. Walker said it was an extraordinary thing, but he had actually worked the engine shown by Mr. Phelps. The photographs, however, were of two dis- tinct engines, the first being a pumping .engine, and the second a winding engine at the bottom of the bank, away from the other. The winding engine was taken down some years ago, but the pumping engine had been in operation until quite recently. In his teens he was interested in that particular engine, and had actu- ally fired a hay wagon boiler with it. The pump did not deliver its water at. the surface, but raised it to the level of the underground canal, which came out to the surface at Worsley. Members might have noticed the red condition of the Bridge water Canal right through Eccles to Patricroft, and that was caused by the water raised at Roughfield, and delivered into the canal at Walkden. He believed it raised ” about 70 gals . per stroke, and one interesting feature was that between the plug rod and valve there was a method of causing a dwell, so that the strokes could be regulated in accord- ance with the necessity for pumping, as shown by an indicator on the wall. He wais inclined to think that was far and away the oldest engine operating within eight miles of Manchester, and he hoped the Bridge- water Trustees had, at any rate, retained some portion of it.- The President asked whether the engine was of the double-acting type. . Aid. Walker replied that both winding and pumping engines were of the double-acting type. The President said he had handled a winding engine very similar to the one shown on the screen that- after- noon, where the slide valve gave steam to the engine at every stroke. Mr. Anderson remarked that the date of the engine referred to by Mr. Phelps could easily be ascertained, because Watt brought out the rotating engine 'after his partnership with Boulton, and that placed it at least not further back than 1770. New Members. The following gentlemen, having been duly recom- mended, were elected members of the Society :— Members, Federated. — Joseph Ellis, Stoneclough, near Manchester; Robt. Vincent Rhodes, Chorlton-cum - Hardy; John Greaves Thompson, Burtonwood, Newton- le-Willows. Associate Members, Federated. — Herbert J. Car- penter, Gelli, Rhondda; Jonathan Tovey, Aberbeeg; Evan William Watkins, WaunllWyd, Mon. Associates, Federated.—Henry Davies, Pontypridd, Glamorgan; Thomas Isaac Davies, St. Fagans, near Cardiff. Student, Federated.—George Haworth, Acerington. Exports and Imports of Coal Products.—The exports of ooal products, not dyes, in December, were valued at £181,46'5, a total below that of £208,003 a year ago, but higher than the £134,009 in December. 1914. The year’s exports reached a total value of £2,801,093, which is substantially in advance of £2,218,167 in 1915, and £2,028,566 in 1914. These figures, of course, relate only to the totals, and not to the prices. The quantities are not indicated in the returns, so that a comparison cannot be made in that direction. The coal tar dyestuffs, which are separately classified, amounted to 2,448-cwt. (3,057 cwt. a year ago), valued at £42,704. During the whole year we exported 5'9,003 cwt., as compared with 36,683 cwt. in 1915, and 46,031 cwt. in 1914. The December imports of coal products (not dyes) totalled 4,861 cwt., as against 2,645 cwt. a year ago, and 4,970 cwt. in 1914. The year’s imports of such products, 34,049 cwt., showed a great reduction on the 54,154 cwt. during 1915, and the 131,778 cwt. during 1914. USEFUL SAFETY CATCH* By W. H. Luxton. The following safety catch is employed in the Sun- flowier Mime, Dugger, Indiana, to prevent cars from running into the shaft sump. This device is simple in construction and easy to manipulate. Fig* 1 is a plan* The parts B-D are made of iron 1 in. thick and about 4|in. wide. The end B is placed against the centre upright of the shaft, the other end D resting beside the track rail A, and extending above it about 6 in. When not being held off the rail by the eager putting his foot on the lever G to allow cars to pass on to the cage, the catch is always held in position ready for action by means of a spring, similar in arrangement to spring latches or switches,' the spring being fastened in the middle of the track at the point F. The catch, or chock, end of this arrangement catches the outer edge of the car wheel, and thus, if the force is sufficient (as in the case of a runaway) throws the car from the track. The car wheels generally extend over the outer edge of the steel rails as much as 2 in., 1 which is sufficient to allow the catch to rest just beside the rail and engage the protruding part of the wheel. Fig.2 Enlarged Section of Part B-C-D Shaft B Fig.I Plan The levers E and G are made of a piece of round iron, in. in diameter. The end E is about 4 in. long, and is maintained in a vertical position by a chain link con- necting it with catch D. The other end of lever G is about 6 in. long, and makes an angle, with the floor of about 45degs., pointing away from the track on which' it operates the safety catch, or chock. The distance from E to G is about 4 ft.; thus when the car is resting against the catch, and the eager gets in position to place the car on the cage, he puts his foot on the lever G, and presses it to the floor. This turns the bar and the lever E sufficiently to withdraw the catch from in front of the wheel. The lever G acts as a foothold until the rear wheels of the car are past the catch. The floor at this point is made of plank about 4 in. thick and 10 to 12 in. wide laid side by side. The catch pivots on the bolt C about 18 in. from the chock D. . . This safety catch is simple, practical, quite- inexpen- sive, and can be installed by any experienced .mine engineer or superintendent. * Coal Age. Coke Motor Vehicles.—Speaking at the annual meeting of the National Steam Car Company Limited, Mr. T. Clarkson, chairman, said that the board were convinced there was a great future for this type of coke motors as commercial vehicles. With coke at 25s. a ton, and petrol at 2s. per gallon, he w£s of opinion, that the saving per mile to com- mercial users would be about Id., and he left them to work out what that meant in the course of a year. When circum- stances permitted the company to adopt coke fuel for its fleet, he had no hesitation in saying there would be a saving to them in fuel alone of upwards of £25,000 per annum. In a report on the coke motor, made by Mr. G. N. Watson, the well-known commercial expert and consulting engineer to the Transport Department of the Ministry of Munitions, he wrote, speaking of the general construction : “ The complete vehicle undoubtedly is a decided advance on all previous steam-propelled vehicles, and to my mind it marks the com- mencement of a new era in road locomotion for commercial purposes.” The authorities had recently authorised the company to proceed with the manufacture of coke motors on a considerable scale, and the shareholders might draw their own conclusions as to the significance of that. Irish Coal and nilectricity.—At a meeting of the Dublin local section of the Institution of Electrical Engineers, a paper was read by Mr. J. P. Tierney on “ The Use of Elec- tricitv for the Industrial Development of Ireland.” Mr.* Tierney said that whilst the mineral and industrial resources of England had been developed to their fullest, the corre- sponding resources in Ireland had hardly been considered. Nearly all the electrical power supply of the country was obtained from seaborne fuel, the cost of which had been very high. Although about 93,000 tons of coal were mined in Ireland in 1914, in no single instance was there a main line railway siding into any Irish coal mine, so that the coal had to be transported by road carts. The result was that the people of Dublin were paying 45s. per ton for coal, whereas Irish coal was being sold at the pit’s mouth in Athy for 15s. per ton, the actual distance from Athy to Dublin being 45 miles. The Advisory Committee for Scientific and Industrial Research should devote some money for the purpose of ascertaining the exact value of Irish coal. As to the development of the peat industry, the only proper course was the erection of a power station practically in the centre of the peat area. The question of the utilisation of Irish peat for power production was one to which the local section should direct the attention of the Advisory Committee.—Mr. David Sherlock, in the discussion, said that a sum of one million pounds had been allocated to these purposes.