To facilitate computations in gauging, Mr. W. Gutteridge has invented a series of new units of measure, which has received the approbation of every individual member of the Commission of Weights and Measures. These units of measure are numbered 1, 2, 3, 4, 5, 6, 7, 8, No. 4 being the common decimal foot, which is introduced to complete the series. These units are all decimally subdivided into 100 equal parts, and are the roots of the cubic and superficial measures in which the capacities of vessels, or solid contents of bodies are reckoned, as gallons for liquids, and cubic feet for timber. By this means, no division is necessary in computing contents or capacities, for the area expressed in Mr. Gutteridge's system of notation multiplied by the depth gives the contents; whereas, when the dimensions are taken in inches, after multi plying the area by the depth, it is necessary to divide the product by the num ber of inches in a gallon or a foot to find the contents. Mr. Guttendge's units of measure, with their data, are as follows : In connexion with the subject of gauging, we may notice a singular circum stance related by Mr. Gutteridge. Ile had been called in to gauge a new vat for Messrs. Booth & Co. distillers, and his own system was employed as affording greater accuracy than the inch method in common use. After the dimen sions had been taken, a glass tube was fixed on the outside of the vat, for reading off the quantities within, as a means of comparison with the interior dip. That no difference might arise from the effect of capillary attraction, the tube was made of more than an inch bore, and was perpendicularly, with a graduated scale placed closely, so that the zero of the scale coincided with the top of the ungula, which exactly covered the bottom, without pro ducing any sensible depth of wet at the dipping place, from which it was inferred that the interior dip, and the exterior indications of level would be always the same ; and upon putting in several determined quantities, those quantities were indicated by the tube exactly ; but a difference was afterwards perceived between the interior dip and the exterior level, and the greater the quantity, the greater the difference. The experiment was frequently repeated, with every precaution to guard against error, one source of which was the difference of temperature in the vat and in the tube, amounting in one instance to 21 degrees, which would cause a difference of about •085 of an inch, (the spirit being 41.6 per cent. over proof,) but to save computations
of this sort, the time chosen for the principal experiment was when the tem perature was alike. With 1400 gallons in the vat, the difference was about •1 of an inch ; 2200 gallons more were then pumped in, and the difference increased of an inch, and on adding 700 gallons more, the difference amounted to inch. It appearing highly improbable that the timbers could compress so much more under the dipping place than under where the tube was fixed, a level of the two surfaces was taken, and, extraordinary as the fact may appear, there was a difference found in the levels, of of an inch, the liquid being that much higher in the vat than the tube. This difference Mr. Gutteridge imputes to a difference in the specific gravity of the spirit within the vat, and that within the tube, and upon assaying them the former was found to be nearly 5 per cent. stronger than the latter. This variation must have been caused by a greater evaporation on the tube, and it shows that with spirits of such great strength. evaporation is very rapid, and cannot be too carefully guarded against. The remaining difference between the dip and the level in the tube Mr. Gutteridge supposes to have arisen from a compression of the timbers under the dipping place.
The following diagrams of the vat, tube, and timbers, will render the subject more intelligible. /7g. 1 represents a section of the vat, a b being the tube fixed into a metal pipe b c, with a cock at c d, the level of the spirit in the vat ; f the level in the tube, and li i the dipping place. Fig. 2. shows the sup ports of the vat ; B the back, and F the front, of which the seven similar parts a a are the immediate rests, each four inches square ; bbb the three timbers upon which the former rest, 10+ inches deep, and 1211 broad ; c c the two sleepers upon which the beams are laid. The places dddd are supported upon four upright posts, and under k was placed another support; I the orifice for the tube pipe, and o the dipping place.