ANNUAL ADDRESS OF THE PRESIDENT. XLIX 
recover its length. Preliminary inquiries were begun on May 11, 
1838, and on June 20, 1843, they resulted in the appointment of a 
Commission to superintend the construction of new Parliamentary 
standards of length and weight, among whose members the Astron- 
omer Royal (now Sir George B. Airy), Messrs. F. Baily, R. Sheep- 
shanks, and Prof. W. H. Miller, were prominent. The laborious 
investigations and experiments carried out by that Commission can- 
not be described here, but it will suffice to say that for determining 
the true length of the new standard Mr. Sheepshanks employed a 
provisional yard, marked upon a new brass bar designated “ Brass 
2,” which he compared as accurately as possible with Sir George 
Shuckburgh’s scale, the two Ordnance yards, and Kater’s Royal 
Society yard. The results in terms of the lost Imperial standard 
were as follows: 
Brass bar 2 = 36:000084 from comparison with Shuckburgh’s scale, 0-36 in. 
36-000280 ” - bs «10-46 in. 
36000303 from comparison with the Ordnance yard, 1A. 
36:000275 “cc ce ce ce cc DA? 
36-000229 from Capt. Kater’s Royal Society yard. 
Mean — 86:000284 
Respecting this mean Mr. Sheepshanks wrote: “This should be 
pretty near the truth; but I prefer 36:00025, if in such a matter 
such a difference be worth notice. I propose, therefore, in con- 
structing the new standard to assume that— 
Brass bar 2 = 36:00025 inches of lost Imperial standard at 62° Fah.”’ 
And upon that basis the standard now in use was constructed.’ 
Turning now to the French standards of length, it is known that 
the ancient toise de macons of Paris was probably the toise of 
Charlemagne (A. D. 742 to 814), or at least of some Emperor 
Charles, and that its étalon was situated in the court yard of the 
old Chatelet, on the outside of one of the pillars of the building. 
It still existed in 1714, but entirely falsified by the bending of the 
upper part of the pillar. In 1668 the ancient toise of the masons 
was reformed by shortening it five lines; but whether this reforma- 
tion was an arbitrary change, or merely a change to remedy the 
141, p. 664. 
