The Baird machine is similar in construction to the Gillott and Copley, with the exception of a projecting arm or jib in the place of a revolving disc. The cutters on the Baird machine are fixed on strong links, and are caused to revolve round a studded wheel on the engine and around another wheel at the end of the projecting arm or jib. This arm can be set to hole to any desired depth up to 5 feet or 5 feet 6 inches, providing the strength of the machine is arranged accordingly. Such a machine is more suitable for cross-grained coal than the Gillott and Copley.

There are in use in America electrical coal-cutters, which are said to work well, and are simple in construction and easy to move about.

Then we have the Stanley Heading Machine. The coal is cut by rotary cutters fixed on arms. This machine will cut from 12 to 15 yards, 5 feet 6 inches diameter headway, in twenty-four hours, and would do much more if the coals could be removed fast enough The motive power in these cases is compressed air, which also ventilates the places of work.

Hydraulic and electric motors are used for various purposes in the mines, and can be taken for unlimited distances, but it is a question now how far electricity can be used with safety in mines. Electric motors for coal-cutting machines would be attended with a certain amount of danger, even in non-fiery mines. Before electric cables are taken into the workings for any distance, and until complete safety is secured, it would be well to consider the safety of the mine. THE COLLIERY MANAGER.-There are few people understand what the duties of a colliery manager are. visions of the various Acts of Parliament alone requires much thought, skill, and judgment. If a manager fails to comply with any of the numerous provisions of the Acts he renders himself liable to fines, imprisonment, and the loss of his certificate.

outside of collieries who Compliance with the pro

A colliery manager's duties are continuous. The changes of the barometer and thermometer have to be watched night and day; the ventilation of the mine has to go on without interruption, and he must be prepared to deal with any emergency, and, as every practical man knows, there are few mines free from almost continual movements due to the extraction of the coal and subsidence of the roof and lifting of the floor, etc., thus rendering it necessary to have strict day and night supervision over the whole of the mine; and it must be borne in mind that though a manager may appoint who he chooses to perform the various duties he cannot relieve himself of the responsibilities. This goes to show the necessity of a manager selecting practical and trustworthy men, but to get such men is most difficult in some districts. The men most fitted for competent men ought to be the practical colliers, but whether it is bashfulness or want of inclination for such work it is difficult to say, but it does appear to be worth the consideration of the steady collier whether he should continue to work at the coal face all the days of his life or prepare himself for a work more suitable for old age.

The number of colliery officials have been largely increased since the Coal Mines Act came into operation, and there is at almost every colliery much greater facilities

for the miners improving themselves than formerly, and properly speaking there never ought to be any difficulty in having properly trained men to act as deputies or competent men.

In conclusion, there are many subjects beyond the compass of my address left untouched. If time had permitted they might have been referred to, but considering I have already trespassed on your time and patience, I must leave them to be dealt with by those more able than myself, and hope some of the members of this Institute will give us their views and the benefit of their experience on modern mining and appliances in all forms.

I daresay many of us often think after the completion of some important work in connection with our duties we may sit down and rest, but experience has taught us, every day furnishes new matter for thought, reflection, and study, and if we have to keep our position and hold our own-to go on with the times-we must not push the new matter to one side, but deal with it, and continue to look as far into the future as possible. Safety and economy greatly depends on this.

I know of nothing requiring more foresight than colliery management.

At the conclusion of his address, the PRESIDENT moved the following vote of thanks to the retiring President:-"That the best thanks of this Institute be given to Mr. Henry Lea for the able, kind, and courteous manner in which he has conducted the business of this Institute during the past year.

Mr. COLLIS seconded the resolution, which was carried unanimously.

Mr. LEA acknowledged the resolution. If, during his term of office, he had been able to afford any information, or to bring any satisfaction, or to do anything in the interest of the Institute, he could only say that it had afforded him very much pleasure.

Upon the proposition of Mr. H. C. PEAK, seconded by Mr. R. S. WILLIAMSON, a vote of thanks was accorded to the members of the Council for their services during

the past year.

On behalf of the Council, Mr. CLARK acknowledged the resolution, and also personally thanked the members for the honour they had done him in electing him Vice-President of the Institute.

STEAM LOOP AND SEPARATOR.

A working model of the steam loop was exhibited and described by Mr. LEA. Mr. SCOTT wished to know whether any use was made of the exhaust steam from the engine; and secondly, would the same thing apply with the steam loop if the engine was placed above the level of the boiler?

Mr. E. B. MARTEN and Mr. H. W. HUGHES also addressed some questions to Mr. Lea.

VOL. II-1890-91.

Mr. LEA said, with regard to Mr. Scott's question as to the exhaust steam from the engine, the steam loop does not deal with the exhaust steam from the engine. It does not profess to do so. I have seen a model in which the whole of the steam from a small model engine was sent back into the boiler against the boiler pressure, but it is but a model, and in practice it would assume such proportions that I think the expense of installing the apparatus would be too great to justify the result. Mr. Scott enquired what would happen if the engine were placed above the boiler level. Well, in that case the water, separated from the steam, would run back to the boiler of its own accord. Mr. Marten asks a question, the first part of which I am not able to answer off-hand. "What power of engine will it require to do the work which the steam loop does in returning the water to the boiler, and of the two, which is the more economical?" I should say that the engine would be the less economical one. As regards Mr. Hughes's question as to economy, there were some trials made on board of three steamboats in the North of England, each fitted with a steam loop. According to the report which I have received, No. 1 loop was not so skilfully applied as the other two. They all went long voyages, and, on their return, the chief engineers reported that as regarded No. 1 there was a saving of 6 per cent. in the coal consumed. On No. 2 there was a saving of 14 per cent.; and on No. 3 there was an equal saving, showing that in cases where the steam loops have been put in properly there has resulted a saving of 14 per cent. in coal. I am unable to give you details of the difference in the application of the loops.

Mr. LEA then read papers descriptive of the Electrical and Cable Tramway Depôts, which had lately been visited by the members.

THE BIRMINGHAM CENTRAL TRAMWAYS COMPANY'S ELECTRICAL

TRAMWAY DEPOT.

BY HENRY LEA, PAST-PRESIDENT.

On Thursday, the 2nd of October last, some of the members of this Institution visited the electric depôt of the Bristol Road Electric Tramway, and on Thursday, the 11th of December, some of the members visited the depôt of the Cable Tramway. On both occasions, by the courtesy of the Directors and officers of the Birmingham Central Tramways Company, Limited, every facility was afforded for the members to examine and to be informed upon the many points of interest belonging to the respective systems.

This paper is intended to be a descriptive account of what was seen on the first occasion referred to, with. a few remarks upon the working of the system.

The electric depôt occupies a space of about 265 feet by 120 feet.

Beginning with the fuel from which the energy is primarily derived, the following are some of the particulars :

The coal store is 37 feet by 30 feet, and holds about 100 tons of coal.

The boilers are two in number. Each boiler generates enough steam to give 100 brake horse-power at the fly-wheel rim of the engine, which is supplied by it. Each boiler is of the multitubular type, 12 feet 6 inches long, and 7 feet 6 inches diameter, with two internal furnace tubes, each 2 feet 4 inches diameter, and 70 boiler tubes, each 3 inches diameter. The gases pass through the furnace tubes to the back of the boiler, then return through the 3 inch boiler tubes to a smoke box at the front, and thence pass through brick flues surrounding the boiler shell to a Green economiser placed in the flue leading to the chimney stack. The working pressure is 120 lbs. per square inch. The boilers are fed either by an injector or by a Worthington pump.

The chimney stack is circular, 110 feet high, and 4 feet diameter inside at the top.

The engines are two in number, each capable of giving 100 brake horse-power at the fly-wheel rim. Each engine is compound, non-condensing, with Paxman patent automatic expansion gear to the high pressure cylinder. The cylinders are respectively 12 inches and 20 inches diameter, with a stroke of 24 inches. They lie side by side and are coupled to cranks at right angles. The fly-wheels are 8 feet 6 inches diameter, and 17 inches wide, and overhang the outer bearings. The speed is about 100 revolutions per minute. Each engine and boiler is intended to do the whole work of charging the accumulators, the second engine and boiler being used as a reserve.

The dynamos are two in number, and are duplicates of each other. They are Elwell-Parker machines, built for a continuous current, shunt wound, each giving 500 ampères at 120 volts, or 60,000 Board of Trade units. Each is driven by a link belt 16 inches wide, running in a belt race lined with glazed bricks. The speed is about 540 revolutions per minute. Slides and screws are provided for tightening the belts when in motion. The belts run with the slack side above, so as to give a better grip of the pulleys. The whole work upon each dynamo consists in charging accumulators for twelve cars, and, in addition, some fixed accumulators from which the depôt is lighted, and from which an 8 unit workshop motor is driven. The engines and dynamos are in one room, about 48 feet by 29 feet, which also contains the main switch board, provided with two Cardew voltmeters, two 600 ampère ammeters, and main and other switches. A 5 ton overhead travelling crane commands the whole of the machinery.

The distributing switch room is 25 feet by 12 feet, and has 32 sets of apparatus for measuring and regulating the current to the 32 shelves of the accumulator platforms in the charging shed. It also has other regulating apparatus for the use of the battery room. The regulation is effected by means of resistances in connec

tion with rheostats.

The charging shed is 72 feet by 62 feet, and contains 4 hydraulic elevators, each having 8 shelves, capable of accommodating in all 32 sets of battery trays of 6 trays to a set, or 192 trays holding 8 accumulators in each tray, making a grand total of 1,536 accumulators upon the shelves at one time. 32 positive cables convey current from the distributing room to the 32 shelves, to which they were originally connected by sliding contacts, but now by insulated cables, of which the slack is taken up by weighted pulleys. The 32 return, or negative, cables are joined together, and go back to the dynamos as one cable. Hydraulic power is furnished by a set of hydraulic pumps and a hydraulic accumulator. The pumps are worked by a separate steam engine. Hydraulic valves enable the attendant to raise or lower each hydraulic elevator so that any shelf thereof may be placed on a level with the accumulator floor of a tramcar. The discharged accumulators are drawn from the car on to a vacant shelf by means of iron hooked rods, the hydraulic platform is then raised or lowered until it arrives at the right level, when the fully charged accumulators are pushed from the shelf which they occupy into the tramcar. As each tray of 8 cells is drawn on to a shelf, or pushed into the tramcar, an electrical connection is automatically established by means of spring contacts.

The running shed is 97 feet by 62 feet, and between each pair of rails is a continuous pit giving access from below to the mechanism underneath the cars. The remaining portion of the depôt affords the following accommodation :Water tower, 30 feet high, supporting a cast iron tank, which holds about 10,000 gallons of water.

Fitting shop, 36 feet by 30 feet, with shafting driven by the 8 unit electric

motor.

Smith's shop, the fan for which is driven by the aforesaid motor.