eer. Ne rE. 
FRIDAY, FEBRUARY 22, 1884. 
COMMENT AND CRITICISM. 
Ir was an old theory, taught in text-books 
of philosophy, that the conclusions of mathe- 
matics were absolutely certain, — quite exempt, 
in fact, from that liability to error which so 
troubles our conclusions on other subjects. 
Yet disagreements among mathematicians 
upon the demonstrable results of their science, 
even if rare, are not wholly unknown. A 
remarkable case of this sort is now seen in a 
discussion which has been going on since last 
summer in the Royal astronomical society of 
London. Mr. E. J. Stone, president of the 
society, and director of the Radcliffe observa- 
tory at Oxford, informed the society that he 
had detected a serious error in the astronomical 
measurement of time, arising from the sub- 
stitution of Le Verrier’s tables of the sun in 
the British nautical almanac in 1864 in place 
s 
of the old ones. ‘To this cause, he claimed, 
were due certain extraordinary errors in the 
tables of the moon, which had perplexed as- 
tronomers for the past tenyears. At thesame 
time he communicated to the Royal society an 
extended memoir, in which he gave several 
elaborate demonstrations of his views. 
These papers no sooner appeared than the 
new theory became the object of attack on all 
sides. Such astronomers as Airy, Adams, 
Cayley, and Christie, in England, as well as 
their French neighbors, published elaborate 
refutations, showing that Mr. Stone was wholly 
mistaken. His carefully prepared memoir was 
refused admission to the Philosophical trans- 
actions. If mere numbers or authority could 
have settled the question, Mr. Stone would 
have been crushed; but he has so far main- 
tained his ground against his numerous oppo- 
nents with a perseverance which we cannot but 
admire, how little soever we may share his 
No. 55.— 1884. 
views. After going on for eight months, the 
discussion seems to be as lively as ever. Its 
most curious feature is, that the questions in- 
volved are purely mathematical. The new 
tables of the sun make the year shorter than 
the old ones by about one and a half seconds. 
Mr. Stone claims that the unit of time is 
changed by this same amount; that is, that we 
are using a new measure of time, which is gain- 
ing on the old one at the rate of three seconds 
every two years, so that it has gone ahead 
thirty seconds since 1864. His opponents 
claim that this is absurd, since it is not the 
year, but the day, which is taken as the fun- 
damental unit; and the change in the length 
of the day is totally inappreciable. As yet, 
the dispute shows no signs of approaching 
its end. 
Ir is stated that the outlines of the plan for 
the Greely relief expedition, approved by the 
Navy department, are practically as follows: 
the relief party to go north in two vessels, 
reaching Upernavik not later than May 15; 
thence to Littleton Island, endeavoring to 
open communication with the Eskimos at Cape 
York. A depot with one year’s supplies, coal, 
clothing, boats, and a steam-launch, shou!d be 
established at Littleton Island by the first ship, 
and left in charge of an officer and two men. 
This vessel would then approach the borders of 
the pack, and push northward at the first favor- 
able opportunity ; the second vessel to cruise 
about the edge of the ice, and hold herself in 
readiness to establish another depot on shore 
in. case the first vessel be lost, and the second 
required to proceed northward in her place. 
Should Smith Sound be comparatively open, 
the first vessel will proceed to form secondary 
depots at or near Washington Irving Island, 
Cape Collinson, and Carl Ritter Bay ; the sec- 
ond, after making a depot at Cape Sabine, to 
proceed north not farther than Dobbin Bay, 
unless required by disaster to the first vessel. 
