It is as a two-seater, however, that the small car bases its claim to popular favour. In the majority of journeys by any sort of private vehicle two is the number for which accommodation is most frequently required. Many owners of large cars have discovered that the occasions on which a two-seater would not serve their motoring purposes are comparatively few. Obviously it is gross extravagance to employ the voracious eater of petrol and rubber upon a service which can be accomplished at a quarter of the cost by a smaller car, at the same speed, with less strain upon the driver and with equal comfort to the passenger. For these reasons the time is at hand when every motor-car owner; however many big cars he may possess, must add to his fleet at least one two-seater for run-about purposes. The large car will be a luxury, the small car will be a necessity--and not only for those who are ordinarily described as wealthy. The time is coming when every man who can afford to go out of town at week ends will find it worth his while to be a motorist, when every suburban house with a rental of over £60 will have its motor shed, and when the small car will be as prevalent upon the country road as the bicycle is to-day. CAR INDEX-MARKS AND THEIR LOCALE One sees every day on the streets and roads cars bearing numbers and letters quite unfamiliar. It is advantageous, in many ways, for the motoriste to be fairly well acquainted with some of the more important index-marks. One can easily remember in the United Kingdom that Ireland’s index-letters all contain the letter I and Scotland’s all the letter S (with two exceptions). England and Wales to date, with very few exceptions, use up the letters A, B, C, D, E and F. London has now four distinct index-marks and no doubt will add to them as the increase in cars may demand. All motor-cars must have an index-mark and a registration number, excepting those owned personally by his Majesty the King. White letters and figures on a black plate are for privately owned cars. Trade vehicles use coloured figures and letters, usually red on a white plate. Trade vehicles usually also have additional letters which are granted them as a trade-mark or for trade purposes. But the index-mark or letter of their locale must, in all instances, be placed first on the plate. Registration need not be effected in the same district in which the car is owned, so that, with some trouble, an owner can have practically any letter she likes on her car. The fee for registration, £1, need be paid only once on any one car, excepting on change of ownership, when a fee of 5_s._ is payable. But with this change of ownership the index-mark and registration number remain the same. If a new index-mark and registration number are wanted, the existing ones can be cancelled and the car re-registered, in any locality, on payment of the full fee. The following are the index-marks in use in the United Kingdom: ENGLAND AND WALES