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The latest stage in the development history of the yard and 

 pound is their definition by Act referred to above, as follows : 

 — " The following standards were constructed under the direc- 

 tion of the Commissioners of Her Majesty's Treasury, after 

 the destruction of the former Imperial Standards in the fire at 

 the Houses of Parliament in 1835 : — 



"The Imperial Standard for determining the length of the 

 Imperial Standard yard is a solid square bar, thirty-eight 

 inches long and one inch square in transverse section, the bar 

 being of bronze or gun-metal ; near to each end a cylindrical 

 hole is sunk (the distance between the centres of each hole 

 being thirty-six inches) to the depth of half an inch. At the 

 centre of this hole is inserted in a smaller hole a gold plug or 

 pin about one-tenth of an inch in diameter, and upon the sur- 

 face of this pin there are cut three fine lines at intervals of 

 about the one-hundredth part of an inch transverse to the axis 

 of the bar, and two lines at nearly the same interval parallel 

 to the axis of the bar. The measure of length of the Imperial 

 Standard yard is given by the interval between the middle 

 transversal line at one end and the middle transversal line at 

 the other end, the part of each line which is employed being 

 the point midway between the longitudinal lines ; and the said 

 points are in this Act referred to as the centres of the said 

 gold plugs or pins ; and such bar is marked — Copper, sixteen 

 ounces ; tin, two and a half ounces ; zinc, one ounce ; Mr. 

 Baiiy's metal No. 1 Standard yard, at 6200° Eahr. Cast in 

 1845. Troughton & Simms, London. 



" The Imperial Standard for determining the weight of the 

 Imperial Standard pound is of platinum, the form being that 

 of a cylinder nearly 135 inches in height, and 1*15 inches in 

 diameter, with a groove or channel round it whose middle is 

 about '34 inch below the top of the cylinder, for insertion of 

 the points of the ivory fork by which it is to be lifted ; the 

 edges are carefully rounded off, and such standard pound is 

 marked P.S., 1844, one pound." 



It is then provided that four copies of the above, made at the 

 same time, should be disposed of as follows : — One copy at the 

 Royal Mint, one at the Eoyal Society, one at the Eoyal Obser- 

 vatory, Greenwich, and one immured in the New Palace at 

 "Westminster. 



The originals are located in a strong-room at the Standards 

 Department of the Board of Trade, at Old Palace Yard, West- 

 minster, just adjoining Westminster Abbey. An immense 

 number of derivatives of these are in the possession of the 

 Board of Trade, and also numerous standards of purely 

 historic interest. All the weighing and comparing instru- 

 ments are deposited in the Old Jewel Tower (in the basement), 



