SECONDARY STANDARDS. 
945 
III. The said Weight of Platinum marked P.S. 1844, 1 lb., deposited in the Office of 
the Exchequer as aforesaid, shall be the legal and genuine Standard Measure of 
Weight, and shall be and be denominated the Imperial Standard Pound Avoirdupois, 
and shall be deemed to be the only Standard Measure of Weight from which all 
other Weights and other Measures having Reference to Weight shall be derived, 
computed, and ascertained, and One equal Seven Thousandth Part of such Pound 
Avoirdupois shall be a Grain, and Five Thousand seven hundred and sixty such 
Grains shall be and be deemed to be a Pound Troy. 
VII. If at any Time hereafter the said Imperial Standard Pound Avoirdupois be 
lost, or in any Manner destroyed, defaced, or otherwise injured, the Commissioners 
of Her Majesty’s Treasury may cause the same to be restored by Reference to or 
Adoption of any of the Copies so deposited as aforesaid, or such of them as may 
remain available for that Purpose.” 
Densities, Errors, and Distribution of the Standards of W dght. 
The first column of the following Table contains the mark or designation of the 
weight ; the second, its density at the temperature of melting snow (with one excep- 
tion) in terms of the maximum density of water; the third, its error, in grains, when 
compared in a vacuum with PS, the new Imperial Standard lb. ; the fourth, its error, 
in grains, when compared with W, the Commercial Standard lb., in air of the tempera- 
ture 65°'55 Fahr., under the pressure of 29*750 inches of mercury at the temperature 
mm 
of melting snow (t=l8°‘7 C., ^=755*64), in Somerset House, or in air for which 
log A=7’07832— 10. The last column contains the name of the place of deposit, or 
of the country to which the weight has been sent. 
Designation. 
Density. 
In a vacuum. 
In air for which 
log A= 7-07832 -10. 
gr- 
gr- 
P.S. 
21-1572 
0-00000 
0-63407 too heavy. 
No. 1. P.C. 
21-1671 
0-00051 too heavy. 
0-63477 too heavy. 
No. 2. P.C. 
21-1640 
0-00089 too light. 
0-63331 too heavy. 
No. 3. P.C. 
21-1615 
0-00178 too light. 
0-63237 too heavy. 
No. 4. P.C. 
21-1516 
0-00314 too light. 
0-63090 too heavy. 
Sp.+v. 
21-1321 
0-00023 too light. 
0-63336 too heavy. 
Troy Pd. T. 
21-1661 
0-52934 too light. 
0-00745 too light. 
Gilt lb. No. 
1. 
8-36134 
0-00732 too light. 
0-01956 too heavy. 
No. 
2. 
8-.34161 
0-03582 too light. 
0-01132 too light. 
No. 
3. 
8-30462 
0-00510 too heavy. 
0-02512 too heavy. 
No. 
4. 
8-36500 
0-00425 too heavy. 
0-03157 too heavy. 
No. 
5. 
8-06122 
0-01783 too heavy. 
0-00734 too heavy. 
No. 
6. 
8-28779 
0-01714 too light. 
0-00083 too heavy. 
No. 
7. 
8-12163 
0-01933 too heavy. 
0-01658 too heavy. 
No. 
8. 
8-16317 
0-01428 too heavy. 
0-01679 too heavy. 
No. 
9. 
7-37614 
0-11611 too heavy. 
0-00426 too heavy. 
No. 10. 
8-28375 
0-03910 too light. 
0-02162 too light. 
No. 11. 
8-36302 
0-04208 too light. 
0-01499 too light. 
No. 
12. 
8-31919 
0-02060 too light. 
0-00118 too heavy. 
No. 13. 
8-43179 
0-03331 too light. 
0-00195 too heavy. 
No. 
14. 
8-34955 
0-02844 too light. 
0-00301 too light. 
Distribution. 
Exchequer. 
Royal Mint. 
Royal Society. 
Royal Observatory, Greenwich. 
New Palace, Westminster. 
Observatory, Altona. 
Royal Observatory, Greenwich. 
India. 
Russia. 
Prussia. 
Bavaria. 
U.S. America. 
Edinburgh. 
Austria. 
Dublin. 
Canada. 
Cape of Good Hope. 
Sydney. 
Portugal. 
Spain. 
Holland. 
