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followed from week to week till the whole have been pre- | complete record of any central station that has ever been sented to our readers, who will then have the most given.

SOLAR STRESS CONSIDERED AS THE CAUSE OF lifting a constant weight, certain printing presses, swing

TROPICAL HEAT.

BY R. C. SHETTLE.

In my paper published in the Electrical Engineer on December 4, I suggested that "solar stress was the cause of tropical heat." I now wish to supplement that paper with a few remarks from a dynamical point of view.

I considered tropical heat as the result of the elastic energy of the atoms, manifested owing to reduction of terrestrial gravitation pressure in the line of the greatest solar stress. The question may be asked: If reduction of this pressure is in proportion to solar or any other external stress, how is it that the moon does not produce more heat than the sun, as its gravitation stress is greater?

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In answer to this another element comes in-viz., the results of the motion of bodies in the production of magnetic phenomena, and the consequent effects which they manifest upon each other. Thus, "no particle of matter is independent. Every atom of matter is in the place and under the conditions it occupies, as a result of the sum of the various forces which influence it."* Again, "magnetic force varies in electromagnets according to two ratios: 1. As the number of turns of wire. 2. As the current passing. We may put the two ratios together and say it varies as the current-turns; or, carrying out the regular evolution of technical terms, we may say, in a given magnetic system the force varies as the ampereturns."*

Now, in addition to the internal magnetic effects upon the earth, etc., by ordinary statical gravitation, we must take into consideration the dynamical conditions, all of which are modified by the nature of the component elements of each mass. We then find that in proportion to the mass, its nature, and the number of rotations, the stress is increased; the character of each atom in this case adding to the dynamical in contra-distinction to the statical effects of stress. Therefore, as the sun is so much larger than the moon, and its magnetic condition so much more active, owing to its mass, the rapidity of its motion and the amount of stress to which it is subjected from a variety of sources, its effects upon the rotating earth ought to be much greater than those of the moon.

A MOTOR OPERATING AUTOMATICALLY AT ANY DESIRED SPEED OR TORQUE AND WITH MAXIMUM EFFICIENCY UNDER ALL CONDITIONS.

BY H. WARD LEONARD.

In the operation of electric motors there are three principal factors to be considered-the speed, the torque, and efficiency. Under any variations in power the efficiency should remain as nearly constant as possible. For one class of work it is desirable to keep the speed constant when the torque varies. For a second class of work it is desirable to keep the torque constant at one particular amount when the speed varies. For a third class it is desirable to operate at many different speeds, and yet automatically at any particular speed desired regardless of the torque. For a fourth class it is desirable to operate at many different torques and yet automatically at any desired torque regardless of the speed; and for a fifth kind it is desirable to keep the amount of power supplied constant, regardless of a change in torque-that is, so that if the torque changes by the requirements of practice, the speed would automatically change so that the power consumed would remain constant. The shunt-wound motor, operating on a constantpotential circuit, is well adapted to the first class of work mentioned, where but one fixed speed is desired, practically regardless of the torque and with a practically constant efficiency.

The second class of work mentioned, having one particular constant torque and a speed variable at will, cannot be performed by existing electric motors without great sacrifice of efficiency. In this class of work we find hoists Electricity," J. T. Sprague, pp. 481 and 510.

bridges, stamp mills, pumps, etc.-that is, such work as requires that we should start up from dead rest with full torque and run at any desired speed with the same torque and with perfect efficiency.

The third and fourth classes of work are more common than would at first appear evident, but since neither the steam engine nor the waterwheel can be operated under conditions where both speed and torque will vary, and where the speed or torque can be held automatically fixed at any point desired, regardless of variation of the other, we do not find work of this kind existing in such shape as to be operated by an electric motor instead of some other power. Nor has the electric motor been available for such duty heretofore. A familiar instance of the third kind of work is met with in the printing of fabrics, where the presses have a large number of rolls upon which the torque depends, and the speed of the presses must be varied as desired, and yet at any given speed must hold that speed constantly regardless of the number of rolls set down-that is, regardless of the torque. Similarly, lathes, drill presses, wood-working machinery, etc., belong to this class. Certain variations in the speed are possible by existing methods by the use of the cone pulleys and equivalent devices, but no motor of any kind has heretofore existed which directly applied could conform to the requirements of this kind of work.

The fourth kind of work has, as a familiar example, the passenger elevator, where the weight, and consequently the torque, is variable, and where at any torque the speed should be controllable at will with constant efficiency. Another example is the pumping of water against a variable pressure with the speed controllable at will, and independent of the pressure. This result is not obtained directly by any motor to-day.

The fifth class of work, where the speed is automatically varied to keep the power consumed constant, no matter how the torque varies, is not met with in practice as far as I know, yet oftentimes we may have a constant source of power from which we wish to get a torque variable to the requirements of a variable load and do not care particularly about the speed. An electric street railway operated by water power is a familiar example of this class of work.

It will be seen from the above that of the five principal classes of work there is only one-namely, constant speed and variable torque-which we can take care of with reasonable efficiency and from our existing supply circuits.

It is well known that when a street car is first started and is scarcely in motion the actual power represented by such motion is almost nothing, for, although the pounds pull is large, the feet per minute is extremely small; consequently the power required must be exceedingly small. What do we find in practice? We find that in order to develop a power of but a fraction of a horse-power we must, on account of the slow speed demanded, develop about 30 h.p., and then waste about 98 per cent. of this horse-power in order to utilise the remaining 2 per cent. in the way it is desired. The efficiency of the modern electric street car is not probably more than 2 per cent. when just starting from dead rest and moving at the rate of one-half foot per second.

When we come to investigate this, we find that the explanation is that in order to get the necessary large torque with freedom from excessive sparking, we must have a very large current in a nearly constant field; and since our E.M.F. is constant, we must use an amount of power which will vary almost directly with the torque, and will be regardless of the speed. Or, in other words, the efficiency of the motor will vary directly as the speed, with an efficiency of perhaps 80 per cent. at full speed. As a result of my investigation of this subject, I have concluded that the operation of electric motors should conform to what apparently is a new law, and which may be stated as follows: Vary the voltage as the speed desired; vary the amperes as the torque required.

In other words, make the speed dependent upon the voltage only and independent of the current, and make the torque dependent upon the current only, and independent of the voltage. Since the product of the speed and torque represents the work being done, and the product of the

volts and amperes represents the power supplied, it is evident that if we can operate in conformity to this law, we shall have a constant efficiency under all conditions, disregarding, of course, the small fixed losses in the field and armature.

One way in which this law can be followed is to supply the field of the motor from one source of electric energy and supply the armature from another source, the E.M.F. of which can be varied. It will be noticed that when the speed is fixed a fixed voltage will be necessary in order to conform to the law, and the shunt motor is found to conform perfectly to the law; but it is the only motor I know of which does conform to the law which seems to be generally applicable.

A simple case will be the operation of a printing press for printing fabrics. Suppose the press has 10 rolls that is, the torque will vary from one to 10 in amount. Suppose also that it must be run at any speed from that represented by one to that represented by 20, and at any speed it must hold its speed constantly, whether one or 10, or any intermediate number of rolls be brought into use. Also that the efficiency must be independent of the speed or torque. In order to conform to the law in a simple way, we will install a generator and motor of the same size and connect their armatures by two conductors. We will supply their fields from a small separate exciter in the shape of a shunt. wound dynamo. In the circuit leading to the field of the generator we will place a rheostat. If now we drive our generator at a constant speed, the E.M.F. it will produce will depend upon its field, which in turn will depend upon the amount of resistance in the rheostat in its field circuits. The strength of the motor field is constant, being supplied by the constant E.M.F. exciter. Now, evidently the speed of the motor will depend solely upon the E.M.F. supplied to its brushes, and this can be varied from 0 to the maximum limit by varying the rheostat, which will preferably be placed beside the motor itself. The current will automatically vary in proportion to the torque, the speed will vary directly as the voltage, and the efficiency will be constant and independent of the speed or torque.

If we wish to operate an elevator from central station conductors of constant E.M.F., we supply a shunt-wound motor mechanically connected directly with a generator, whose armature is connected to the armature of the elevator The field of the generator is supplied from the central station conductors, but a loop goes up to the elevator car, where a rheostat and reversing switch are placed, so that the E.M.F. of the generator can be varied and reversed at will. The field of the elevator motor is excited from the line constantly.

It will be evident that we can control the elevator perfectly from the car and run in either direction, at any desired speed, and with perfect efficiency. It is worthy of notice that the non-sparking point is entirely independent of the speed, and that for any particular weight the nonsparking point is absolutely fixed and independent of the power used. Also that, since the maximum weight alone determines the maximum amperes, it will be impossible to send more than the normal full load in amperes through the armature; consequently the liability of burning out of armatures is reduced to a minimum. The elevator in coming down generates current to assist the central station, and since the efficiency is practically constant under all conditions, and since as many foot-pounds of work are done by the elevator in descending as it requires in ascending, the consumer will in reality pay only for the energy wasted in charging the fields, in heating the armatures, and that represented by the friction of the gearing, which will be the least possible. The starting up of the elevator requires a minimum of power, and hence does not subject the central station to large, sudden fluctuations of load.

Suppose we want to operate a swing bridge by an electric motor. We connect, as in the case of a printing press, but instead of a hand field rheostat we use an automatic field rheostat, such as is used by the Edison company. We place an ampere-meter in the armature circuit of our motor, and when the ampere-meter needle indicates full load it touches a contact leading to the relay magnets of the automatic rheostat, which causes it to throw in resist ance in the field circuit of the generator and reduces its

E.M.F. Similarly, just below full load, the ampere-meter needle makes contact, closing a circuit in the automatic rheostat so as to throw out resistance and raise the E.M.F. of the generator.

To start up the bridge we insert all of our resistance in the field of the generator, and have, let us say, no volts. Now we close the main line switch to the motor. We will have no current, hence the ampere-meter needle will be on the lower contact, which will gradually throw out resistance and cause the generator to generate an E.M.F. The current will increase, and will finally cause the needle to leave the lower contact, The full torque is now being developed, and the bridge, if the motor be of proper size, will start to move. As it does so the counter E.M.F. of the motor will tend to reduce the current, but this will cause the needle to again make the lower contact and raise the E.M.F. and speed and hold the current and torque

constant.

Thus the bridge will start from rest with a minimum of power but full torque, and will gradually accelerate in speed until the full E.M.F. and speed of the motor is reached. To vary the speed by hand we merely move the ampere-meter needle to make either contact desired. In case the bridge should meet an obstruction which would slow it down, the amperes would not increase, but would remain constant, as the volts would be immediately and automatically reduced to just that amount necessary to keep the amperes constant. With this arrangement it will be practicably impossible to overload the motor armature.

Another good application of this method of keeping the turque constant will be in any case where a tool is cutting certain material which may vary in hardness, or when the feed may vary. If the torque be kept constant it will be impossible to break the cutting tool or injure the apparatus. An electric coal-cutter is a case in point. The cutter may be advancing through slate, fireclay, or coal, and occasionally it will meet a layer of hard iron pyrites, known in the mines as "sulphur.' This may stop the cutter-bar entirely, and with an ordinary or series or shunt motor the result would probably be a burnt-out armature. With the system I have described the current would be constant in any event, and the current would automatically go faster in soft material and slower in hard material.

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Leonard's Automatic Motor.

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In pumping by an electric motor operated on this system the head alone determines the torque, and hence the current. Consequently, for any lift the none-sparking point will be fixed, and the number of strokes per minute can be controlled at will, from 0 up to the maximum by varying the volts.

For operating an electric railway we will place a shuntwound motor on the car, and directly driven by this motor will be a special generator, which will be connected to the electric motor below the car. It is evident that the generator and working motor armatures may be wound for any voltage desired, say 20 volts, which will make the problem of insulating the street car motor an extremely simple one. If desirable, we can supply several cars of a common train from one special generator on the forward car. With this outfit we will be able to take any car up any practicable grade or around any curve with no more power than is required to move the car on a level, and always consume the same power, regardless of weight, grades, or curves. That is, the automatic increase of current, to take care of any increased torque, will be compensated for by a corresponding decrease in the volts and speed. We may start a car up on any grade or curve with but a small fraction of the power required for normal speed on a level.

I wish to call attention to a very important development

leading out from this—namely, that we will be able to use alternating currents for operating our street cars, for it is well known that the ordinary alternating-current generators will operate perfectly as motors, if the speed and torque be kept constant. Since by this system we can, from a constant torque and speed, get any other torque and, automatically, a corresponding speed, we shall be able to run street cars perfectly by alternating currents. This, again, will enable us to dispense with trolleys, conduits, storage batteries, etc. We will place between our tracks, in manholes, converters whose primary pressure can be anything required for proper economy and whose secondary will be, say, 15 volts. This secondary circuit will connect directly with the rails. The road will be divided in sections, each a few hundred feet long, and each section will be supplied by its own converter.

This system also lends itself very readily to the transmission of power. We may transmit by alternating currents, and the alternating-current motor running at a constant speed and at a nearly constant torque will drive special generators to operate hoists, pumps, locomotives, etc., at the varying torques and speeds demanded by practice, and yet without subjecting the alternating-current motor to a sudden or wide fluctuation in its torque and without any necessity of varying its speed. With this system of operating electric motors there seems to be no work met with in practice which cannot be perfectly performed.

On first consideration, the additional apparatus necessary would seem to make the system prohibitory in practice; but the capacity of the present single motor is greater than the combined capacity of the apparatus this system would require, and the capacity of the prime motor is very much reduced.

In order to reduce the first cost to a minimum and yet secure the advantages of different automatic speeds and high efficiency, I have devised two modifications of the arrangement described above. The first is adapted to power in which a smooth, efficient acceleration of a load from rest is required, as in the case of passenger locomotives and elevators. The second case is where various automatic speeds are desired, but no especial importance attaches to the starting of the load from rest, as is the case in machinery in general.

For the first case we have the trolley system of electric street cars as the most important. Let us suppose we have two motors of 15 h.p. each for the car. We find that for full speed upon a level we require about 15 amperes at 500 volts. Upon heavy grades we find that about 50 amperes are required, and, as before, we have 500 volts. With this consumption of energy we find that we get a speed upon the heavy grade which is about one-quarter of the speed upon a level. In order to operate upon my system, let us place upon the car a motor generator, the motor part of which is wound for 500 volts and 12 amperes and the generator part of which is wound for 125 volts and 50 amperes. The fields of the motor and generator part are distinct, and are wound for 500 volts, as are the fields of the two propelling motors under the car. All these fields are supplied from the 500-volt trolley circuit. In the field of the auxiliary generator is placed a rheostat.

Now, suppose the car at rest upon a grade. The motor generator is running, but the generator has a very weak field. Its armature is connected by a controlling switch to the propelling motors. We now gradually cut out resistWe now gradually cut out resistance from the generator field circuit, and finally get about 20 volts at the brushes of the generator. With this E.M.F. we get sufficient current to produce 50 amperes through the armatures of the propelling motors in a saturated field. This gives us the full torque, and the car starts at a speed of perhaps half a foot a second. This speed can be maintained constantly and indefinitely, and the consumption of energy will be less than 2 h.p. This is less than three amperes from the trolley line. In practice, however, the speed will be rapidly but gradually accelerated, until we have 125 volts upon the terminals of the propelling motors. We will now be running at one-quarter speed, and will be consuming 125 volts and 50 amperes-that is, 6 kilowatts instead of 25 kilowatts to get the same result with existing motors. To put it another way, we will not be using as

much energy as is represented by the 500 volts and 15 amperes necessary for full speed on a level.

The next step on the controlling switch will disconnect the armatures of the propelling motors from the auxiliary generator and put the two armatures in series across the trolley line direct. We will now go at a speed represented by 250 volts-that is, one-half full speed. The next step of our switch will place the two armatures in multiple across the 500 volts, and the next and last step will place the 120-volt auxiliary generator in series with the main central station generators, and give us 625 volts on our armatures and a correspondingly increased speed. We will be able to go up a grade of 6 to 8 per cent. at full speed, with 50 amperes and 500 volts, which, with the present motors, gives only about one-quarter of that speed.

Under this arrangement it will be noticed that the only apparatus which could be called additional is the small motor of 500 volts for the generator part of our motor generator, which is useful, not only for starting, but for full speed also. In stopping the car we have an electric brake action delivering back energy to the line at full efficiency and not through a rheostat, as at present.

If we have a train of, say three cars, so that we have six motors, we can start from rest with sufficient smoothness by placing all six armatures in series, which will give us something less than one-sixth speed as the first step. Then we can place three in series with two multiples, which gives us one-third speed. Next, two in series with three multiples, which gives us one-half speed; and finally, all in multiple, which gives us full speed. Under such conditions, we can dispense with the small converting plant altogether.

For an elevator requiring, say, 15 h.p. we will put in a motor generator of 3 h.p., with which we will control the starting and stopping and the operation up to one-fifth of full speed. Then for full speed we will connect direct to the line and operate without any conversion of energy.

For power in which smoothness of motion in starting and stopping is not essential I have devised a new system of distribution, as follows: three dynamos all having the same current capacity and having voltages of 621, 125, and 250 respectively, are placed in series and from conductors led off in multiple, one from each terminal of the machines. These conductors will have potentials which can be represented by 0, 621, 187, and 437. Let us now take a shunt-wound motor, and, disconnecting the field from the armature circuit, excite the field from the outside two of the four conductors, that is, by an E.M.F. of 437 volts. By connecting the armature terminals to the four conductors in various ways we shall be able to operate in either direction at six different automatic speeds represented by the following voltages: 62, 125, 1871, 250, 275, 437. By varying the field strength of the motor we can, if required, get any intermediate speed.

In many cases two dynamos will answer, one of, say, 110 volts already in use for incandescent lighting, and a second of, say, 30 volts. With this arrangement we could run in either direction and with automatic speeds represented by 30, 110, and 140.

With the four-wire six-voltage system of distribution in a shop we can take out all countershafting, belting, pulleys, and gears, if desired, and place a motor upon every tool, which we can operate in either direction at any automatic speed desired. Lathes, planers, and all tools can be perfectly operated, and by getting rid of all countershafts and belts we can introduce the greatest of modern tools, the travelling crane, which we will also operate from our general system. We can also readily operate ventilating fans, hoists, elevators, and factory tramways from the system.

The addition of one dynamo and one new conduotor to any existing three-wire system will probably give all the flexibility required to meet practical conditions of varying speeds. For the alternating system a synchronous motor driving our three continuous-current generators will give us the four-wire system in any distant factory or town. For 500-volt street railway circuits a small motor generator plant for the slow speeds and a direct connection for full speeds will give us perfect results. For storage battery work we have the most perfect condition, as we can get

small provincial towns or rural districts the undertakers are able to satisfy your department that underground work would mean

any E.M.F. desired, with a corresponding speed while keeping the field separately excited. Now that we have the rotary field at command, I think prohibitive expense, or for any other reasons would be impractic

I may safely assert that the time is not far distant when we shall have transformers which will, without motion, convert an alternating current in the primary into a continuous in the secondary; and this seems to me to be the ideal system of the future-that is, one in which energy will be transmitted by alternating currents of constant E.M.F. transformed without motion into continuous currents for use at the translating devices and used where motors are concerned in conformity with the law of efficiency for motors: Vary the voltage as the speed desired; vary the amperes as the torque required.

MEMORIAL TO THE BOARD OF TRADE.

The signatures of all electrical engineers is desired to the memorial emanating from the London Chamber of Commerce:

To the Right Honourable Sir Michael Hicks-Beach, Bart, M.P.,
President of the Board of Trade, Whitehall, S. W.

SIR, -We, the undersigned, electrical engineers, electrical contractors, and others interested in the distribution of electrical energy, have the honour to address you on the subject of the Electric Lighting Acts of 1882 and 1888, and desire respectfully to submit to you the following observations on the subject of the use of overhead conductors in rural districts.

We are aware that in the case of the metropolis and of large towns your department has already decided that overhead conductors can only be permitted as a temporary arrangement, and that all permanent conductors must be laid underground. Whilst we are of opinion that that decision may even yet have to be reconsidered in the light of subsequent experience, we are anxious to make it perfectly clear that in this communication we have no wish to question the correctness of that decision, but we desire to emphasise the fact, that a marked distinction exists between undertakings which are to be carried out in the metropolis, in large cities or towns, and undertakings in small provincial towns or rural districts; and we beg leave to submit that however cogent may be the reasons which have led your department to decide against overhead conductors in large towns, such reasons do not apply with the same force in small towns or in rural districts. The objections to overhead conductors, based upon the inconvenience to traffic and the danger to life, are in the country far less serious, if not altogether absent, whilst on the other hand the advantages which such conductors afford are greater.

As regards the safety of the public-a consideration to which, as we are aware, your department is always bound to attach the utmost importance-we would submit that absolute prohibition of the use of overhead conductors is not necessarily consistent with increased security to the public. When overhead conductors are erected in conformity with well-considered regulations, and under proper supervision, the possibility of danger resulting from their use is so remote that it may be disregarded in view of the advantages gained. It may, in fact, be less than would be occasioned by the use of the underground mains.

With regard, on the other hand, to the advantages which are offered by overhead conductors, we would point out, that in the case of small towns and rural districts, the probable consumers of electric light will (at first, at any rate) be situated at relatively considerable distances apart, and consequently undertakers will have to use long stretches of conductors in order to reach such consumers, and this they can only afford to do by the use of overhead conductors. We are of opinion, therefore, that unless new discoveries should enormously reduce the cost of the work to an extent which at present we see no reason to anticipate, it will be a practical impossibility to introduce electric lighting in country districts except by means of overhead conductors; therefore the adoption of a fixed rule, that all conductors must be carried underground, would mean an absolute prohibition of electric lighting in such districts. Another and almost equally important question arises out of the use of electricity for motive purposes. We are of opinion, that for the purposes of electric traction in rural districts, overhead conductors will be found to be the only mode on which long lines can be made commercially successful, and that a fixed rule which forbade their use throughout the United Kingdom would seriously retard the development of electrical motive power.

In view of these circumstances, we respectfully urge that your department should not lay down as a settled principle that no overhead conductors should be allowed, but that, in the rural districts at least, the circumstances of each particular case should be allowed to determine whether overhead work should or should

not be sanctioned.

In conclusion, we beg leave to say that while we concur in the view that the use of overhead conductors should be regulated as stringently as the public interests may require, we think that the electrical engineering industry should not be hampered by their being unconditionally forbidden; and we submit that wherever in

able, and that the objections to overhead conductors would be so
slight that they might be disregarded, sanction should be given to
the erection of overhead conductors, subject to such regulations
and restrictions as experience may show to be necessary.
Botolph House, E.C., December, 1891.

CORRESPONDENCE.

"One man's word is no man's word
Justice needs that both be heard.'

OMNIBUS WANTED.

SIR, Where is the electric omnibus? Now that the electric exhibition is about to open at the Crystal Palace it should be shown there, and be put on to run from the London, Brighton, and South Coast Railway low-level station to the Parade entrance of the Palace. It would be a help to visitors to the exhibition, and if can do that service it will do anywhere.—Yours, etc., W.

FINANCIAL ADVICE WANTED.

SIR, I have taken five shares in the Electric Tramcar Syndicate. Would you oblige by giving your opinion on the tramcar? Yours, etc.,

December 7th, 1891.

[We insert the above letter as a sample of what information we are supposed to give. Undoubtedly we do usually know something of financial matters connected with electrical companies, but it is impossible to advise on these matters through the columns of a technical journal. In this particular instance we are asked for an opinion as to the merits of a tramcar from an investor's point of view, whereas such an opinion, if given in our columns, should be from an engineer's point of view. Some directors obtain dividends for their shareholders with really nothing to work, others cannot obtain dividends with the best of apparatus in their hands. Such are the wonders of finance. Our correspondent has really gone too far before seeking advice. He should have sent before, not after taking shares, and then we might have been tempted to emulate Punch, who occasionally advises.-ED. E.E.]

SHIPPEY BROS., LIMITED.-A DISCLAIMER.

SIR, Our attention has been called to the announcement under the head of "City Notes," p. 552, in your journal of the 4th inst. We have to state that we have not purchased shares nor are we shareholders in the firm of Shippey Bros., Limited, to which reference is made, and we have to request you to contradict this statement in your first issue.Yours, etc., GWYNNE AND CO.

Victoria Embankment, W.C., Dec. 9, 1891.

The Royal College of Surgeons, Dublin.-The president and council of the Royal College of Surgeons, at Dublin, have been making important alterations and additions of a most extensive character, which will make the schools the most perfect of their kind in the kingdom. A spacious new dissecting-room has been built, together with preparation-rooms and the necessary apartments requisite for anatomical study, and also a new physiological theatre and laboratory. It is further proposed to reconstruct the chemical laboratory and to erect pathological and bacteriological workrooms, and the council have recently decided to have the whole of these schools, together with the college itself, lighted electrically. They accordingly retained Messrs. Waller and Manville, 39, Victoria-street, Loudon, S. W. (who, it will be recollected, are also acting as consulting engineers to the Dublin Corporation for the city central station), to advise them on the matter and supervise the work. Having invited tenders, the council accepted that of the Electrical Engineering Company of Ireland, it being the lowest and the most satisfactory.

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