HYDROCARBON OIL (Hansard, 3 March 1971)

§ Mr. Michael Cocks (Bristol, South)
I beg to move Amendment No. 1, in page 1, line 13, leave out 60°F' and insert 15.5 recurring degrees C'.

The Deputy Chairman
It might be for the convenience of the Committee to discuss at the same time Amendment No. 2, in line 13, leave out '60°F' and insert '15.5 recurring degrees C (288.5°K)'.
Amendment No. 3, in line 14, leave out '60°F' and insert '15.5 recurring degrees C'.
Amendment No. 4, in line 14, leave out '60°F' and insert '15.5 recurring degrees C (288.5°K)'.
Amendment No. 5, in line 18, after '210°C', insert '(483°K)'.
Amendment No. 6, in line 20, after '23°C', insert '(296°K)'.
1856 Amendment No. 7, in Clause 2, page 2, line 17, leave out '60°F' and insert '15.5 recurring degrees C'.
Amendment No. 8, in line 17, leave out '60°F' and insert '15.5 recurring degrees C (288.5°K)'.
Amendment No. 9, in line 24, leave out '60°F' and insert '15.5 recurring degrees C'.
Amendment No. 10, in line 24, leave out '60°F' and insert '15.5 recurring degrees C (288.5°K)'.
Amendment No. 11, in Clause 3, page 2, line 30, leave out '60°F' and insert '15.5 recurring degrees C'.
Amendment No. 12, in line 30, leave out '60°F' and insert '15.5 recurring degrees C (288.5°K)'.

§ Mr. Cocks
That would be convenient, Miss Harvie Anderson. I hope to be able to deal with these Amendments briefly. It is with some trepidation that I step into the deep waters of trying to amend a consolidation Bill since I know the severe limitations on attempting to do so.
There are 12 Amendments in my name, the form of each being very similar. In Clause 1 it will be seen that there are mixed units of temperature measurements, degrees Fahrenheit and degrees Centigrade.
Hon. Members will remember that on 15th February this year we changed over to the decimal currency system. What many members of the general public do not yet fully realise is that the whole nation is committed to a total changeover from the existing Imperial system of weights and measures to a metric system of weights and measures, which is due to come into force at some time by 1975. Britain has also agreed to change over to the international system of units which is known as the S.I. system.
I am suggesting that we should drop Fahrenheit and use Centigrade, and that in addition we should give the basic unit of temperature on the S.I. system the degree Kelvin equivalent. The use of Fahrenheit is obsolete. It seems to me absurd not to take the oportunity in consolidating this legislation to get rid of this obsolescent terminology. I understand that consolidation Bills occur only from time to time and that a substantial number of years may elapse before this 1857 process is gone through again, and we shall be fossilising something that has long fallen out of use.
The Joint Committee took into account the changes which have taken place and converted the old tax rates into decimal currency. Therefore, we are entitled to ask why Fahrenheit was left. We see from the Joint Committee discussions that their reasons for not doing so are recorded. The problem which apparently was the great stumbling-block was that 60 degrees Fahrenheit when changed into Centigrade becomes 15.5 recurring. The Joint Committee felt that this was not practicable and that it was not possible to work with any great degree of accuracy with such a recurring decimal.
I would point out that huge areas of higher mathematics are based on two numbers, pi and epsilon. As the Committee will know, pi is the ratio of circumference to diameter of a circle. Much effort was spent trying to work out its exact equivalent. In 1882 it was eventually proved that it could not be worked out exactly. But an even more important number in mathematics is epsilon, which is a transcendental number, the sum of an infinite series, and can be worked out to the approximate value required for any degree of accuracy in working. One cannot help thinking that had the Joint Committee had Aesop's famous fable posed to it, he would have cleaned up a large sum of money, because to a man, on this thinking, the Committee would have backed the tortoise as opposed to the hare every time.
The Joint Committee did not convert to Fahrenheit, because it felt that it would be impracticable to work with this figure. This is not so in practice. The Committee said that it might cause confusion and that people might have to obtain different kinds of thermometers. When we consider the upheaval which the country has experienced in changing to decimal currency and the large sums spent on converting cash registers, those arguments seem thin.
This opportunity will not occur again for some years. I ask the Solicitor-General to accept the Amendments, which are proposed in the spirit of trying to bring our legislation into line with modern thinking, to give a Centigrade equivalent for the Fahrenheit, and, in 1858 brackets after that, the international S.I. unit, the Kelvin degree equivalent.

§ The Solicitor-General (Sir Geoffrey Howe)
I cannot invite the Committee to accept the Amendment. Nature endowed us with the figure of pi, with which be have been bedevilled in our schooldays, and we all have to live with that, preferably in the form of 22 over 7 rather than in its indefinable decimal form. It would be taking purity and modernisation too far to fly in the face of the advice and conclusions of the Joint Committee and to write into a Statute Book the figure 15.5 recurring.
No such thermometers exist. The trade which has been accustomed to handling these figures in this way, by reference to Fahrenheit, on the one hand, and to Centigrade, on the other hand, has not demanded this change and would not welcome it. If the occasion arose at a future time for changing to a different temperature scale, it may well be that it would be found difficult to do so in such a way as to avoid a recurring decimal, which is not something for which one feels a boundless affection, especially in an Act of Parliament.
I suggest to the Committee that it should accept the advice of the Chairman of the Joint Consolidation Committee and agree that it does not wish to pursue this extremely complex and rather curious paradox any further, and that it is as well to consolidate this part of the law in the way in which it has been in previous Bills, unless and until a movement towards different temperature scales takes place.