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test pressure is 450 lbs. of steam and 800 lbs. hydraulic pressure.

The boiler is carried on a circular frame, which is bolted on to the main frame of the Chassis. Within this circular frame a superheating coil is fitted, the length of tube in the coil being sufficient to raise the temperature of the steam to about 750° Fahr.

The burner is contained in a steel box of conical form, the interior of which is lined with asbestos and sheathed with nickel, in order to prevent the disintegration of the asbestos by vibration on the road. The burner case is bolted up to the lower side of the aforementioned circular frame, and the flame is distributed over all the tube plate.

This arrangement enables either the burner or boiler to be removod or exchanged without interfering with the other part. The burner is fitted with an automatic controlling device, operated by steam pressure, and an indicator is provided in front of the driver by which he can see at a glance the size of the flame, whether the burner is in full commission, or whether it is shut down to a low flame.

The control of the feed-water into the boiler can be automatically governed by a thermostat, but in some cases a simple foot valve is used, and no difficulty has been experienced with this arrangement in practice.

In front of the driver is a wheel controlling the supply of steam, and this and the steering wheel give him control completely over the running of the car.

There is a foot lever operating an outer band brake on each driving wheel, and a hand lever operates an internal expanding break on each driving wheel. The hand lever may be locked.

The exhaust steam from the engine is conveyed to the condenser, which is located in the fore part of the car. This, while preventing the appearance of visible vapour, increases the distance capacity on a single charge of water, and largely obviates the necessity for replenishing, the time occupied in which has to be deducted from the running or earning time.

ACTUAL RESULTS IN USE.

It is interesting to note the results of the running of this set of machinery, and as a public service was started at the beginning of last November, and maintained over two months without intermission with one car, it is easy to get at the running costs, there being no difficulty in locating the charges to each individual car, as would be the case if more than one car were in commission.

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essential, and the pit should preferably be equipped with connections for attaching the cable of a portable electric inspection lamp. The bottom of the pit should have a good slope towards a sump or well, and on each slde of the pit runners may be fitted to enable a light bogey to be run under the cars for the convenient handling and removal of the burner box or engine, the parts being lowered from the car and run out on the bogey beneath the level of the floor.

The replenishing of the water and fuel

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FUBLIC SERVICE CAR.

GARAGE EQUIPMENT.

One of the important adjuncts to the satisfactory running of a public service of motor cars is the garage equipment and organisation. This must be so arranged as to enable a car to be handled, whether for cleaning or replenishing, inspection, renewing, or adjustment, with the greatest facility and expedition, for it must be always remembered that when a car is in the garage it is not earning, but on the contrary is an expense.

An inspection pit, over which a large number of cars may be run, is absolutely

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must be done through large bore pipes, so that a car may be replenished in the shortest time possible. Certainly, with proper arrangements, this need not exceed two minutes, and within the writer's knowledge, it has been done in 45 seconds. It is necessary to have an efficient arrangement for measuring accurately the quantity of fuel supplied to each car, and a good clock is necessary to ensure regularity in the starting of the cars.

Each car ought to have a separate lock-up cupboard for the care of cleaning materials, stores, and spares, and clear instructions

exhibited in the garage as to the daily duties of both the drivers and cleaners. This will help to keep them up to the mark, and makes for efficiency.

A resident garage engineer should be held responsible for the cars being inspected each morning before they are allowed on the road, and he should have the assistance of experienced mechanics for effecting an overhaul. A rigid system of inspection is necessary for the cars before being sent out each morning, and at the end of the day's work, and a diary kept of any work done and any parts renewed on each car.

The entrance to the garage and the exit should be carefully arranged to simplify manœuvring and getting over the pit, and it will be best if the cars first pass through the washing area before proceeding to their allotted berths, each one having access to the pit if necessary, and able to be removed from the garage without necessarily disturbing the rest.

DRIVERS.

One of the most important matters, especially with a large public service, is the provision of an adequate supply of reliable drivers.

It will be a prime necessity to select for drivers, active, quick-witted, sober, and well conducted men, train them thoroughly in the use of the car, test their powers of steering and stopping and handling the car, before putting them on the road, and insist on their making themselves acquainted with the mechanism, so as to know when anything appears to be amiss, and correct it at once. Handy men, of the blue-jacket type, or who would be smart drivers of omnibuses or hansoms, are the kind of recruits wanted.

Although it is not necessary for the driver of one of these cars to be a trained mechanic, it is necessary that he should be in possession of his senses, and a careful test ought to be made of his fitness to be entrusted with the responsibility of driving a public service car.

First of all his eyesight should be tested, both for accuracy and colour blindness.

Second, his quickness of action should be tested by a communication through the senses both of sight and hearing.

In addition there might be a nerve test for his steadiness under sudden and unexpected disturbance or interference.

It is believed that much may be effected in this direction by purely mechanical methods,

and the enhanced value of the would-be driver is thereby increased to a far greater extent than is represented by the expense of the trial.

It is therefore suggested that a school for drivers is desirable, in order that they may be made familiar with the general construction of the car, and at the same time furnish an opportunity of selecting the best men, and eliminating the wasters.

Having selected the driver and fairly started him on his duties, it is suggested that his remuneration be a fixed wage, plus a monthly bonus, the award of which depends upon keeping the car regularly in commission.

It has also been suggested that a special bonus be paid to those drivers who, by caring for the tyres, avoiding stones when possible, and the too sudden application of brakes, have the power to considerably reduce the cost of the tyre maintenance. The writer is of opinion that these suggestions embody a sound commercial principle, which it is worth the while of all who are interested to take note of.

DISCUSSION.

Colonel R. E. CROMPTON, C.B., said he had hardly any destructive criticisms to offer on the paper. The author had struggled through immense difficulties, and had performed two great achievements by making a car which was good enough to work for public service and by making it work with It was far too much the habit of the paraffin. public, which saw a large number of pleasure vehicles running in the streets, to think that motor cars were in a very advanced stage. Undoubtedly the motor car driven by petrol was a very perfect pleasure vehicle to those who could afford time and money, but with the notable exception of Mr. Burford's cars very few cars had been put into public service. Cars had been put on the streets, but had been withdrawn, one of the principal reasons for which was that there were dangers and risks attaching to petrol when it was used in very large quantities, in addition to its high price. It was well known, as the author said, that theoretically a steam engine used more fuel than the internal combustion engine, yet, on account of being able to use very cheap fuel compared with petrol, Mr. Clarkson succeeded in producing a result in the reliability trials which, for equal weights, was 40 per cent. better than the best petrol motor, a very fine achievement. Mr. Clarkson had shown the steam engineers of England the astonishing result that a comparatively small-sized steam engine had beaten the internal combustion engine on its own ground. He had done that by a combination of many beautiful features, each of which taken by itself would

have been creditable, but taken together in one car, the observer was apt to undervalue them because they were so many and all good. It was a marvellous result to have been able to run 1,019 miles without experiencing the trouble of the blocking of the burner. The difficulty connected with burning paraffin was that carbonaceous deposits were formed in the narrow passages; and it showed the forethought and care the author had devoted to the subject that he had been able to secure the success he had done. Mr. Clarkson had also embodied in the engine some most beautiful features; he had thoroughly case-hardened and ground the parts; he had substituted for the very annoying packing in the glands, which had always to be renewed, the very beautiful system of solid floating phosphorbronze bushes, an interchangeable system of pumps, and a system of lubrication, each of which was worthy of great merit. But he thought the old and well tried type of boiler, which the author had used after making experiments with more modern and better types, was not the best. He (Colonel Crompton) had had considerable experience of the modern types of boilers, and both the White and Miesse flash boilers were far more likely to give satisfaction, to cost little in upkeep, to be perfectly safe in use, and never give trouble with bad water, as was the case with the multitubular and very expensive type of boiler the author had adopted. He thought the excellence of Mr. Clarkson's performance in the reliability trials reflected the greatest credit on English engineering generally. More originality had been shown in the design of the cars described, than in the whole of the cars shown in the recent French exhibition, about which so much had been said. That was a great feather in the cap of England, and Mr. Clarkson should be sincerely congratulated on it.

Mr. E. SHRAPNELL SMITH said the first point which appealed to him was the reference to the question of steam omnibuses versus electric traction. He agreed with Mr. Clarkson that a great many authorities in this country had become so devoted to the fetish of electric traction, that they had gone ahead more rapidly in electric traction than was justifiable. He did not refer so much to large centres of population, such as London and other large cities, but there were many towns in England with a population of 60,000 or 600,000 which borrowed £200,000 to spend on trams, when they could, by means of the motor omnibus, carry out the whole of the service required for about one-sixth of the capital expenditure, greatly to the relief of the rates. He hoped, through the paper and the discussion, it would be brought to the notice of the different authorities which wer contemplating going in for systems of electric traction that there might be just cause for investigation in that direction. Mr. Clarkson had referred to the failure of the vehicles that had been put on the road.

A great deal of the failure was due to the cause that the light Chassis, designed for pleasure purposes, had been overloaded. The notoriety the failures received had given a distinct set back to the use of selfpropelled public service vehicles, which was, to a great extent, undeserved. The author had referred at some length to the question of drivers. He thought one feature in comparing the driving of a public service vehicle propelled by an internal combustion engine as compared with the steam engine was, that in the latter the engine was never out of gear, but with a petrol motor, the driver, in climbing a hill, had to step down three or four times, and even the man who drove a pleasure car very often misjudged the momentum of the car, and damaged his car in consequence. Mr. Clarkson had referred to over-driving. He thought the makers would have to produce machines which must comply with all the ordinary business exigencies of public service, even if they were over-driven; they must be made strong enough to be over-driven. Mr. Clarkson's car looked as if it would stand a lot of over-driving without any serious result. He had been amused at the moral the author of the paper drew when a little butterfly petrol car happened to knock up against his car. Probably if Mr. Clarkson's car had bumped into a big petrol car the result would have been different. The system of lubrication adopted was one which must appeal to everyone absolute automaticity in lubrication was a great gain. As the author pointed out, it was not the actual cost of the replacement or repair which was the important factor, but the loss of earning power. The machine was tied up for a day or two, and no income was made from it. Mr. Clarkson had given a sketch of what he thought was a proper arrangement for a garage, but no provision was made for it in his estimate of cost. There was a very good margin between the estimated income per mile of 13.2d. and the cost of working, 5'48d., to cover the supervision, management, and general charges. Personally, he did not think that unless, in a public passenger service, one could see one's way to a certain income of about 10d. or d. a car mile it would pay, taking all charges into account. He was quite in agreement with Mr. Clarkson, when he said it was desirable to have spare parts in case anything broke; if there was trouble with the boiler or the engine, it it was very handy to lift them out of the frame and drop in new ones; but he would like to know what was the weight of the engine as shown. In looking at the photographs he had been struck with the fact that, having regard to recent design, Mr. Clarkson had preserved a considerable amount of curvature of the springs. He wished to ask whether the author had any reason to consider them superior to the flatter springs which were now more generally used. His own experience was that where there was a big curvature, there was a good deal of frictional play between the plates, and that the flatter springs of the railway type were the better. With regard to the

exhaust valves being underneath the cylinder, the author mentioned that when the driver had been standing with a car and then started, the water which had accumulated ran out. But there was a further advantage in having the exhaust valves on the under side of the engine. He had seen many designs of steam engines where the exhaust pipe came away above the level of the cylinders, and there was gradual condensation in the pipe, which ran back into the cylinder, and, on several occasions, this had blown out the ends of the cylinder. In regard to the boiler tubes, were they screwed at either end, or were they merely expanded in? It was cheerful to hear that tyres were only going to cost Id. a mile, but the estimate that they would run for 20,000 miles was based on the statement that they had run 3,500 miles, and had only been reduced an inch in diameter. He had endeavoured to get makers to guarantee their tyres for 5,000 miles, with not very encouraging results. As Mr. Clarkson was using a tyre which was giving better results than he had been able to obtain hitherto, he would like to ask whether the makers of the tyres gave a guarantee that they would run a certain distance. The proposal for the establishment of a school for training drivers was a good one, but it would have to be at his own works; and if he was prepared to train them there it would be a great assistance in getting the cars adopted and successfully used on the road. The secret of making a car a success was to pay the driver on the bonus system; and the principle should be adopted that if the car was broken down and in the shed, the man was also broken down to a considerable extent in his wages.

Sir EVAN JAMES, K.C.I.E., referred to the excellence of the engines of the author's cars, which, on being taken to pieces after running 3,000 or 4,000 miles, were found to be as good as new, owing to the system of lubrication adopted. There was no doubt a necessity for good drivers, as the mechanism contained in the cars should not be placed in charge of an ignorant person, and no doubt arrangements would be made to send out competent people in charge of the cars to avoid break-downs.

Mr. EDWIN N. HENWOOD thought the figure of £60, which the author had given as the cost of a set of tyres, was very much below the actual cost; he was informed that the price was £120. It should also be considered, from an engineering point of view, whether it was not far better to put the resilient material in the place where the minimum quantity would give the maximum effect. It was very cruel to put all the resilient material-rubberon the outside of the wheel, where it was ground away, and where it very often caused serious injury; and there was also the drawback that the brake could not be applied with any great power without militating against the endurance of the tyre; whereas if one

third of the quantity of rubber which was now put on the tyre was put into the hub of the wheel, five times as much resilient power would be obtained from the rubber as was now got by using it as a tyre, and it would probably last for ten, or more, years without renewal.

Mr. GODFREY BREWER said the two principal problems which had arisen in connection with cars, were the boilers and the wheels. The style of boiler which Mr. Clarkson had adopted, had, in the past, proved most unsatisfactory. In the table giving the cost of renewals, the repairs to the boiler were stated asnil," but he noticed from the paper that the vehicle had only been at work two months and a week. He would very much like to know what the result would have been at the end of six months, as he had found that, at the end of six months, boilers fitted with partially submerged tubes usually required renewing. Also, in the design of boiler used, there was no possible means of cleaning the boiler internally, except by washing it out with a hose pipe; it was impossible to remove the scale from the tubes; in fact, the boiler had to be worked until it required renewal, or a new boiler was put in its place. Until somebody designed a boiler which had totally submerged tubes, or produced a device which would recover a far greater proportion of the condensed water than was at present the case, he did not think there was much chance of the boiler used by Mr. Clarkson giving successful results. As far as wheels were concerned, his experience was with wheels not fitted with rubber tyres. Of course, rubber tyres considerably saved the wheels, but the cost of the tyres had to be put against that. He thought it was rather doubtful whether it would pay to continue to use rubber tyres. He quite agreed with Mr. Smith's remark that because a tyre ram 3,000 miles, and only wore half an inch, there was no reason to hope that the tyres would continue to at that rate. As far as the upkeep of tyres was concerned, he found that very few makers of tyres would guarantee them, but he had heard of one maker who quoted a price of 1d. per mile for maintaining the tyres.

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Mr. WALTER WHITE thought that for cars for public service work steam was the only practical system. The need for change-speed gear was a great drawback to the internal combustion engine. He thought Mr. Clarkson had been guilty of one inconsistency. He had warned his audience not to overload the cars, and yet he himself used one uniform style of Chassis, but sometimes with a light body and light load, and at other times with a heavy body and heavy load.

Mr. J. H. KNIGHT asked what was the mean speed at which the public service vehicles ran when travelling on the road.

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