THE BITER BITTEN.
 Unconscious humour such as is provided by the enclosed letter which was recently published in the Daily Express, although perhaps somewhat misguided, should be appreciated by your readers, both employers and employees, and I would particularly draw attention to the title.
TO-DAY'S HUMAN STORY—HIS OWN TEST.
" He had driven motorcars for 33 years. Was proud of his spotless licence. Was one of the greatest advocates of the Road Traffic Act. Actually sat on the committee that considered the Act. Was himself driving near Canterbury. Stopped by the Police. Told that he was exceeding the speed limit in the built-up.' Sat up straight in his driving seat. Was astonished, and could not credit it. You pick on me,' the police said he replied, 'because I have a smart-looking car. Why I helped to make these laws, and I should not want to break them.' Canterbury magistrates yesterday unmoved. And Sir Frank Bernard Sanderson, Conservative M.P. for Ealing, paid his £,5 line . . . whilst, after 33 years, his licence joined the ranks of the spotted."
When one considers the hardship endured by some of our drivers when thrown out of work for doing about 2 m.p.h. over the speed limit on 20-m.p.h. vehicles, and the fact that these men are actually driving for about 75 per cent, of their working time, we feel that the Daily Express should collaborate with your staff for the provision of more suitable material to place under this heading. They seem to be running short.
Belton. B. MILLICHAIVIP.
for Millichamp.Bros., Motor Transport.
RATE-CUTTING RUINING THE INDUSTRY.
 It is with great interest that I read your valuable journal every week. I see that recently you published some notes about the owner-driver as a protection to the industry. I have a good deal to say on this question, being one myself.
I used to operate five lorries, but through so much cutting in prices I gave up several of them. For a long time I have obtained 15s. per ton for goods from Cardiff to Port Talbot and that area, but we have in Cardiff, I am sorry to say, firms who do the same work for half the price. There is a lot of talk but the chief question is how are we to stop this? I was one of this first to join an association In Wales, being under the impression that members of such an organization would be honourable from the business standpoint. Some of the cutting firms were reported by me but no notice was taken.
I lost the work for one lorry because I would not cut the price. Then I happened to be a bit busy one day, and the firm for whom I was doing haulage were also busy and wanted some goods at once. Naturally, said, " Tell them at Cardiff to send the goods down, there are plenty of haulage contractors there." The goods were sent, and the charge was exactly half the price I was quoting. This has meant my losing the work.
What is the best to do? Some say "join an association." As I have already stated, I was one of the first to 'do that. But I find it is no use. I was up at a licensing court, the G.W.R. was against me. I asked the association what help I could have, from it. "Oh, get a solicitor" was the only advice I received.
If you report these cutters of rates you get nowhere at all and become only a marked man. When is all this going to end? I can give full particulars of all I write and the names of the haulage contractors who do this work.
I find it best to stand on my own and keep several of the lorries idle. The serious thing is that these people are, by their attitude, giving work to the railways and forcing other vehicles off the road.
In nine cases out of 10 you will find that those cutting rates are members of some organization.
WHITHER ROAD TRANSPORT?
(4740f I am sorry if my omission of the word "politically" when quoting Mr. Walter Gammons, inconvenienced him. I did not think it necessary. It really does not matter how the railway companies are becoming stronger, even to the point of annihilating commercial road transport, when Mr. Garam'ons had maintained such was inevitable, it being, as he said, the only thing for them to do, etc. I did him no injustice when I suggested that he was inconsistent. Surely I was justified in protesting in a courteous way, for where is the logic in his definitely admitting the inevitable success of the railway companies' object, and later, writing "If this calamity is to be avoided, the road transport interests must act at once." What is the use of fighting the inevitable?
I do not see that I can, with advantage, add anything more to that which appeared in my previous letter, beyond admitting the .superior knowledge of Mr. Gammons on the practical side of road transport, but I must retain to myself the claim that my interpretation of his article was that which any ordinary intelligent person would place thereon.
WHEN SHOULD ENGINES BE DECARBONIZED?
[47411 It would be interesting to know to which type of vehicle A.J.H. (letter 4729) is referring, as any goodclass modern engine running on the average grade of fuel and lubricating oil, should return at least 20,000 miles before decarbonizing and valve r grinding become necessary. If anything, long-distance work is more favourable to the maintenance of engine tune, as the engine then works under more efficient conditions.
Much depends on cylinder size : it will generally be found that relatively small engines, i.e., units having individual cylinder capacities of less than 750 c.c. per c61
cylinder, will require attention rather more often than the larger units. This type of engine is usually built more to a price than a specification, it runs at a considerably higher crankshaft speed and often the mechanical maintenance is conspicuous by its absence.
Ii is possible to build engines that will not require valve rectification for ,at least 50,000 miles, but this cannot be done while price is often the first and last consideration.
As regards the 'heavier class of lorry, I can offer plenty of opportunity to drive vehicles that have not been decarbonized for upwards 'of 40,000 miles. He can take his choice of either petrol or oil engines with four or six cylinders, and if he is ever passing through Newcastle, I extend to him a cordial invitation to call and make some tests on any vehicle under my care.
There are only two reasons why an engine should require a top overhaul. These are excessive carbon deposit on the combustion chambers or on the ports and valves, and leaky or eroded valves and valve seats. As lubricating oil is the principal source of carbon, it becomes a question of keeping excessive oil from the combustion chamber, and this is a problem that should be solved in the drawing office before the engine goes into production. Much the same applies to valves. An inefficient combustion chamber will quickly burn the best of valve steels, with consequent power loss.
Censidering the present stage of development of the internal-combustion engine, and the small power outputs per litre of the present-day lorry engine, the question of valve rectification should not arise between overhauls. The fact that some engines require stelae seats to give reasonable valve life is in itself an admission of something not as it should bein the design of the unit.
With the present-day technique of engine design, at least 70.000 miles should be possible before cylinder reconditioning becomes 'netessary, and given adequate bearing size, together with some of the modern bearing materials, crankshaft rectification should not be necessary during the life of the engine.
Now for a last grumble. Why not give us jacknuts on all cylinder heads? A single-piece six-cylinder head is not by any means easy to remove when held fast by carbon and' corroded studs.
Newcastle-on-Tyne. J. L. G. BREWSTER,
for Orrell and Brewster.
CONVEYING DANCE PARTIES TO HOTELS.
 I think that "Hirers" (letter 4736) should be given additional advice to that given in your reply.
They should be informed as to the provisions of Section 25 of the Road Traffic Act, 1934, under which most private-hire work would have to qualify if the ,vehicle is to be used as a contract carriage under Section 61 of the 1930 Act. Unless sightseeing in London comes within those provisions, a road service licence will be as necessary for that work as it would be for the conveyance of parties from London to those hotels, within a radius of 30 miles, that arethe unhappy possessors of sparsely populated dance floors, and in this latter case irrespective of whether separate fares are charged or not—as was decided in the Hackney Stadium case.
They should also be advised that as it would seem that the dance work would be done within the special area of the London Passenger Transport Board, then they would additionally require the consent of the Board before they could operate.
, As is usual i1 all things, I have left the best to the last.:." Hirers " state.: "Hitherto we have never operc62
ated coaches of our own, preferring to hire them as required," and my advice is that they should leave themselves in the position that they can always make
that statement. F. A. FUN, Director, London, S.E.4. For M.T. Co. (Motor Coaches), Ltd.
THE POWERS OF P.S.V. EXAMINERS.
 What are, the factors which public-servicevehicle examiners take into consideration when granting or_.renowing certificates of fitness, that is as regards the duiation-of such. certificates? .Is•the duration of a certificate of fitness determined by the year of manufacture of the vehicle, or its general mechanical condition, or both?
Can you also inform me as to what constitutes the maximum period for a certificate of fitness and whether any appeal can be made against an examiner's decision if the operator considers that the period for which the certificate of fitness is granted does not do justice to the vehicle? W.E. Evenwood.
[A certifying officer appears, under the Road Traffic Act, 1930, to have absolute discretion in the issue or revocation of a Certificate of Fitness. The vehicle must, of course, comply with the statutory conditions of fitness. The maximum period of validity of a certificate is five years, but if a certifying officer think fit he may issue one for a shorter period, so long as it be for not less than a year. The duration of the certificate would undoubtedly be influenced by the year of manufacture of the vehicle, as well as by its general. mechanical condition, because a certifying officer is not likely to issue a certificate for a full five years if the vehicle were, say, six years old. If the holder of a certificate is aggrieved by the refusal of a certificate, by the limitation of its duration, or by its revocation, he may appeal to the
• Minister of Transport.—En.]
HAULIERS NOT USUALLY COMMON CARRIERS.
 I shall be grateful if you could perhaps give me a decision on the undernoted problem.
A consignment of 12 cases of confectionery was transported by motor lorry a distance of 50 miles for transhipment to steamer. A clear signature was obtained by the driver from the shippers, but when the goods were ultimately delivered at their destination the contents of two cases were found to be damaged, although the shippers, in their case, received a clear signature for the consignment.
The merchant forwarding the goods claims on the contractor to make good the loss, as the shippers repudiate liability.
Is a contractor liable as a common carrier although a clear signature was received?
Glasgow, W.1. W. TRUEMAN, J1UNR.
[A common carrier is one who holds himself out as being prepared to carry the goods of anyone who wishes to employ him, but a haulage contractor who, whilst holding himself out as a contractor, decides in each case whether or not he will accept a consignment of goods which is offered to him is not a common canier. As a general rule haulage contractors are not common carriers. This is the rule in England, and so far as we are aware it applies also in Scotland. If, as we assume, you are not a common carrier, it would be necessary for the merchant forwarding the goods to prove that the damage was caused while they. were in your custody and that the damage was due to the negligence of yourself or your employees. In the event of the merchant's pressing his claim we would advise you to place the matter in the hands of a Glasgow solicitor, who would take the matter up on your behalf.—End