Dimensions for British stu 1 ard spanners, publication 192-1924, The BE.S.A. has just published Publication No. 192-1924, dimen: of British standard spanners, which are given all dimensions necessary for setting out spanners to the new British standard design, to 2" nominal size. Dimensions for British standard spanners were in the Association's Re-
28 in 1908, but owing to criticisms on. the design in that report it has been re-considered and the British standard recommended is based on a design which has been well tried out in practice.
The table of dimensions is preceded by notes regarding the angle between spanner head and shank and the method of marking, which provides for marking with both the BSW. and B.S.F, bolt sizes. jergines should satisfy themselves, by test or otherwise, which of the four grades of oil specified can most satisfactorily be utilized in any scien engine, and the corresponding specification should then be adopted, There are one or two points of spec-in! interest in these specifications, as follows:
(a) No mention of specific sgravity is made, In the past many specifications have culled for 4 definite viscosity, but the conclusion has been reelled that It is unnecessary to specify the specific gravity of a fuel oil provided the viscosity charaeteri: ties are clourly. defined.
The sulphur content isnot specified. While drawing up these specifications every effort was made obtain evidence to prove that the harmful effects attributed to oils in certain eares were due to the sula phur in the oil. Pending the pi duction of such evidence it has been Jaoeided Uhat, in the euse of fuel fil for heavy-oil engines a diss Uinet from fuds for use under be Jers, a test for sulphur unnecessarily increases the cost of the oil.
'The specifications will be revised, nosessary, in 12 months' thine.
The methods of testing the oil given in these specifications ara those adopted by the Institution of Petroleum Technologists, and are described in detail.
Text read from the printed page and cleaned; old type leaves the occasional error.