1887.] ^t)D [Taylor. 



experiments, the British pavlianient have not yet acted in the form of law " 

 (Reijort to Congress). 



Just five hundred years after the statute of 17th Edward II (A.D. 132-t), 

 enacted that " three barley-corns round and dry, make an inch— twelve inches 

 make a foot," etc., the first change was made in the legal definition of the 

 foot. By the act of 5th George IV, c. 71 (1824), it is declared "the standard 

 yard is the distance between the centres of the two points on the gold studs 

 in the straight brass rod now in the custody of the Clerk of the House of Com- 

 mons, whereon is engraved 'Standard yaid, 1760,' the brass being at the tem- 

 perature of 62 degrees of Fahrenheit's thermometer." "The Yard, if lost, 

 defaced, or otherwise injured, may be restored by comparing it with the pen- 

 dulum vibrating seconds of mean time in the latitude of London, in a vacu- 

 um, on the level of the sea, the yard being in the proportion of o6 inches to 

 39.1393 inches of the pendulum." This was the first attempt to refer the 

 English foot to a natural standard. 



Ten years afterward, or in 183-4, the contingency provided for by this sta- 

 tute actually occurred by the burning of the Houses of Parliament ; in which 

 conflagration the celebrated brass standard of Bird was destroyed. Although 

 the only actual legal standard was thus lost, no attempt was made to restore 

 it by the pendulum, as provided by law ; but the mean of several different 

 standards, including one belonging to the Royal Astronomical Society (for- 

 tunately the Astronomical Society had procured a most carefully prepared 

 copy of the imperial standard yard, and the Mint was in possession of an 

 exact copy of the pound), was selected as giving the nearest approximation 

 to the legal standard yard. 



A commission was appointed by the British Government, in 1888, " to con- 

 sider the steps to be taken for the restoration of the Standards of Weight 

 and Measure." The commissioners in their report, made in 1841, say : "We 

 are of opinion that the definition contained in the Act 5, Geo. IV, c. 74, ss. 1 

 and 4, by which the standard yard and pound are declared to be respectively, 

 a certain brass rod and a certain brass weight therein specified, is the best 

 which it is possible to adopt. Since the passing of the said act, it has been 

 ascertained that several elements of reduction of the pendulum experiments 

 therein referred to are doubtful or erroneous; thus the reduction for the 

 weight of air was erroneous ; the specific gravity of the pendulum was 

 erroneously stated, the faults of the agate plates introduced some degree of 

 doubt, and sensible errors were introduced in the operation of comparing the 

 length of the pendulum with Shuckburgh's scale, used as the representative 

 of the legal standard. It is evident, therefore, that the course prescribed by 

 the act would not necessarily reproduce the length of the original yard. 

 Several measures however exist, which were most accurately compared with 

 the former standard yard. And we are fully persuaded that, with reasonable 

 precautions, it will always be possible to provide for the accurate restoration 

 by means of material copies which have been carefully compared with thorn, 

 more surely than by reference to any experiments referring to natural con- 

 stants." And the report concludes by recommending " that the standard of 

 length be denned by the whole length of a certain piece of metal or other 

 durable substance, supported in a certain manner, at a certain temperature ; 

 or by the.distance between two points or lines engraved upon the surface of 

 a certain piece of metal or other durable substance, supi)orted in a certain 



