8o 



SCIENCE. 



[Vol. XXI. Na 523 



most accurate. The latest determination of the mass of a cubic 

 inch of water is that of Mr. H. J. Chaney, superintendent of 

 weights and measures in London, which was communicated to 

 the Royal Society on Feb. 4, 1890. Mr. Chaney ascertained th.e 

 weight of water displaced by three bodies, which he designated 

 respectively by the letters C, Q, and S They were: — 



C, a platinized hollow bronze circular cylinder, 9 inches in di- 

 ameter and height. 



Q, a quartz cylinder, 3 inches in diameter and height. 

 S, a hollow 6 inch brass sphere. 

 With these he found as follows : — 



In normal air a cubic inch of distilled water, freed from air, at 

 the temperature of 6i° F. , was found to weigh — 



C 353 267 



S 353.301 



Q 252.261 



By normal air is meant ' ' Air a.t t = 62° F. ; p = 30 inches, con- 

 taining four volumes of carbonic-anhydride in every 10000 vol- 

 umes of air, and also containing two-thirds of the amount of 

 aqueous vapor contained in saturated air, weighed at Westminster, 

 latitude 51° 29' 58" — at 16 feet above sea-level. A cubic- inch of 

 such air weighs 0.3077 of a grain " 



The International Bureau of Weights and Measures is engaged 

 in the investigation of this constant, and when its conclusions 

 are published the question will probably be definitely disposed of 

 for a long time to come. 



The Troughton 82-inch scale was formerly accepted as a stan- 

 dard of length, but for many years it has not been actually so re- 

 garded. By reason of its faulty construction it is entirely un- 

 suitable for a standard, and for a long time it has been of historic 

 interest only. Since its rejection as a standard the United States 

 yard has beeu considered as identical with the imperial yard of 

 Great Britain, the material representations of which are two ac- 

 curate copies, made and presented to the United States at the 

 time of the adoption of the imperial yard. 



The standard of mass has been the avoirdupois pound, identical 

 with the imperial pound of Great Britain, except for purposes of 

 coinage, for which the standard is the Mint Troy pound, brought 

 from London in 1837, and which was legalized for this purpose by 

 Act of May 19, 1828, and re-enacted in the year 1873. 



As, with a single notable exception to be referred to later, this 

 is the only legislation by Congress upon the subject of standards, 

 it is important to inquire by what authority the standards above 

 mentionedexistassuch. Professor Mason has indirectly answered 

 this. Congress having failed to take advantage of its constitu- 

 tional privilege of establishing a uniform system of weights and 

 measures, it became necessary to provide standards for the ex- 

 ecutive departments, by means of which taxes and revenues could 

 be determined and collected. As the Treasury Department was 

 mostly concerned in these matters, the question of standards was 

 left to it. To the first superintendent of the Coast Survey, Mr. 

 Ferdiaand Hassler, was committed the task of constructing stan- 

 dards having the necessary degree of precision, and he was made 

 superintendent of the Office of Weights and Measures. The 

 Troughton scale was brought to this country by him early in this 

 century. A part of it was selected as the standard yard. In the 

 absence of legislation, it will be seen that the standards of the 

 United States Government were tho?e approved as such by 

 the secretary of the Treasury, on the recommendation of the su- 

 perintendent of Weights and Measures. In the mean time, it 

 was known that there was great lack of uniformity among the 

 various States. To encourage such uniformity Congress, in 1836, 

 authorized the construction of copies of the various standards 

 used in the Treasury Department, to be distributed to the gov- 

 ernors of the several States. This action was taken by the Office 

 of Weights and Measures, and did much to bring about uniform- 

 ity. At once many, and finally nearly all. of the States made 

 these copies their standards, and thus practical uniformity was 

 secured. Theoretically or rigorously, however, there are about 

 as many systems of weights and measures in use to-day as there 

 are States in the Union. There are cases, indeed, in which no 

 legislation whatever has taken place, and, while there are severe 

 penalties for the use of false measures, there is nothing to fix 



what measures are true, except, of course, as custom or common 

 law controls. 



The additional national legislation referred to above is the Act 

 of 1866, by which the metric system was legalized over the whole 

 country. This is interesting and important as being the one- 

 single hit of general statute upon the subject of weights and 

 measures. 



In 1875 the International Metric Bureau was organized. To it 

 practically all civilized nations are now contributors. Its object 

 was to construct and distribute prototype standards of the metre 

 and kilogramme to the various contributing nations. These 

 standards were completed and distributed about three years ago. 

 The seals upon the standards for the United States, metre No. 27 

 and kilogramme No. 20, were broken by Benjamin Harrison, 

 president of the United States, on Jan. 2, 1890, in the presence of 

 James G Blaine, the Secretary of State, William Windom, the 

 Secretary of the Treasury, and a number of gentlemen distin- 

 guished in the various professions in which precision in measure- 

 ment is highly regarded. 



They have thus been accepted as standards of the first authority 

 in this country, second only to the International prototype metre 

 and kilogramme of the International Bureau at Paris. 



The metric system having thus received the recognition of the 

 only general legislation by Congress and of executive approval, 

 it has been determined that both the necessities of practical 

 operations in weighing and measuring and tlie demands of precise 

 metrology will b^ best met by referring the units of the customary 

 system to those of the infinitely more perfect and rapidly becom- 

 ing universal system based on the metre and the kilogramme. 

 The relations of the respective units are now so accurately known 

 that this may be done with an approximation entirely satisfac- 

 tory. 



Fortunately the law of 1866, in its table of equivalents, is based 

 on these relations as then known, and later investigations have 

 only tended to confirm the value of the yard in metres as there 

 defined. Thus the wisest course is also the easiest, and the yard 

 and pound, as known in the Office of Weights and Measures, are 

 now defined as a certain part of a metre and a kilogramme, re- 

 spectively. 



Tiiese definitions are as follows : — 



-, ^ 3600 



1 yard = metre. 



3937 



1 pounl =0.453597 kilogramme, according to the statute of 

 1866. 



Or more accurately — 



1 English pound = .4535924377 kilogramme. 



These two values differ by approximately one part in one hun- 

 dred thousand. T. C. Mendenhat.t. 



Office of Weights and Meaeures, Washington, B.C. 



Easy Method of Calculating Complex Surveys. 



A METHOD of calculation employed by Mr. L. M. Gr^iham, 

 manager of the McLean Co. Coal Co., of this place, is new tome» 

 and may be useful, or at least interesting, to some of your readers. 

 In the payment of royalties on ooal mined, many exceedingly 

 complicated underground surveys must be made. the computations 

 of which are very difficult. Having made on a piece of tracing 

 paper a plat of the survey, in all its windings, he transfers this 

 plat to a piece of cardboard; and then cuts away the cardboard, 

 making an opening the exact form of the plat. The cardboard 

 containing this opening is then attached to a smooth surface as a 

 back. As a measure, he has made in cardboard an opening one 

 inch wide and several inches long; and down the edge of this 

 has marked a scale; one square inch representing one hundred 

 square feet. Taking very fine shot, he fills with this the opening 

 in the cardboard representing the plat, taking pains to see that 

 the shot lie but one deep; then pours these out into the measure; 

 and readily makes his estimate. The manager says the plan was 

 thought out by himself; and if a similar plan has been used else- 

 where, he has not known of it. It strikes me as being in- 

 genious, and widely applicable to complicated surveys, whether 

 below or above ground. R. 0. Graham. 



Bloom'iUgton, IIU., Jan. 25. 



