454 
LIEUT. -COL. A. E. CLAEKE ON STANDAEDS OE LENGTH. 
where K is the length of the klafter — that is to say, a correction of 
1 240 2 
1036942 “ 
-1*48 
has to he applied to ,r++ = 163-91. We have therefore finally this result, that the 
Pulkowa klafter exceeds two lengths of the half klafter by 162-44, or 
K'=2Kj+162-44+0-38. 
The Milan Copy of the Klafter. 
The Milan copy of the Austrian klafter, which is deposited in the Observatory of 
Brera, in charge of Dr. Schiaparelli, was, at the instance of Professor Charles Littrow, 
Director of the Observatory at Vienna, borrowed by the Imperial Academy of Sciences 
of Vienna from the Italian Government, and sent to Southampton, under charge of 
Dr. Edmund Weiss, to be compared with the yard and other standards. We shall 
denote this bar by the symbol K". It is a bar of soft Styrian iron, 0*86 inch in breadth 
and 1*31 in depth. The upper surface has inlaid plates of platinum at its extremities, 
carrying clots, the distance between them being the klafter. At the left end of the bar 
is the inscription “ K. K. Polytechn. Institut in Wien 1856,” and in the centre “Wiener 
Klafter bei fi-lo 0 Ileaum. (Mass, cler Punkte).” The lower surface has three dots, on 
inlaid platinum plates, marking the klafter and its subdivision into halves. The dots 
on the upper surface are marked I, II, those on the lower surface are marked 1, 2, 3. 
The bar is supported on points about one fourth and three fourths of its length ; as in 
the Pulkowa klafter, small brass pieces or feet are screwed to the bar to insure an inva- 
riability in the supporting pressures. 
The dots on this bar are very large, and this circumstance introduces a considerable 
amount of discord in the observations. The centre dot 2 is the largest. 
Between April 17th and 22nd ten comparisons were made in the same manner as for 
the Pulkowa klafter, at a temperature of about 50°, and fourteen between July 6th and 
12tli, the temperature varying from 60°*7 to 62 0, 5. 
The observations being reduced in the same manner as described for the Pulkowa 
klafter, give 
Ki. 2 =Ki + 66 - 73, 
K".3=K,+72-91. 
Hence, at the temperature of 6T J *25, the Milan klafter exceeds two lengths of the 
Ordnance half klafter by 139-64. The probable error of this determination is 
+ 0-865^/-4205= + 0-561. 
This is a large quantity, and is due, in great measure, to the large size of the dots. 
The extreme dots 1, 3 on this bar measure about 115 divisions in diameter, and the 
central dot 2 measures 135 divisions, which is equivalent to 107 millionths of a yard. 
