286 PROCEEDINGS OF SECTION E. 
To explain the special importance of the just given explana- 
tion, it is to be stated that thereby can be proved that Professor 
Peters applied quite the same mode of carrying out these im- 
portant measurements with the identical apparatus, including 
pendulum, comparator, brass bar and all. It is by the descrip- 
tion Peters has given in his report in the “ Astronomische Nach- 
richten, No. 2305 Bd. 97 Abth. III.,” that we arrive at the con- 
viction of the thorough identity of the manipulation in question, 
and thereby of the possibility of comparing the observations 
made at Melbourne with those carried out by Peters at Altona, 
Koenigsberg, East Prussia, and Berlin. This was examined 
and proved to be correct by Professor Helmert, Potsdam. 
CoMPARISON OF THE Brass Bar witH VARIOUS STANDARD 
MEASURES. 
Ever since the calculations of the observations had been com- 
pleted (i.e., the end of 1867), I was exceedingly anxious to have 
the brass bar as frequently compared as it proved to be possible. 
It soon became evident that a complete agreement between all 
the comparisons could not be obtained. I deferred publishing 
the results until some comparisons with several of the various 
standard offices could be carried out. There was a comparison 
in the first instance made with the standard bar of the geode- 
tical surveying office at Melbourne by Mr. Ellery in 1864, prior 
to my departure to Europe. In the course of time comparisons 
of the brass bar of Lohmeier were effected at the Normal 
Eichungsamt, Berlin, in 1869, and another one in 1870, and 
next at the Standard office of Great Britain, London (Mr. Chis- 
holm). In the years 1872, 1880, and 1896 comparisons again 
were carried out with a view of eliciting the reason for the dis- 
agreement of various determinations bearing upon the actual 
length of the brass bar. At last it was discovered that some of 
the comparisons had not been referred to Clarke’s celebrated 
comparison of standards.* 
After this had been accomplished, a complete agreement of the 
various measurements could: be achieved. According to Clarke’s 
determinations it was established that 1 yard is 8 / greater (t'= 
0.30479727) than formerly adopted; but besides that it is re- 
quired, in passing over to the international meter, that a further 
enlargement of about 12 # was to be added, which is 20 « to 1 
yard and 24 » to 1 meter (see, for instance, Die Europiische 
Lingengradmessung in 52 deg. long., erstes heft, pages 231-240). 
In consequence of these reflections we arrive at the fact that, 
according to Mr. Ellery’s comparison in 1864 at Melbourne— 
Brass bar = 1 m. + 0.438 mm. 
* A. R. Clarke and H. James.—Comparisons of the Standards of Length of England, 
France, Belgium, Prussia, Russia, India, and Australia, made at the Ordnance Survey 
Office, Southampton, London, 1866. 
