Marcu 7, 1884.] 
After the winter quarters had been prepared, it was 
the intention of Holm to examine the fiord of Fred- 
ericksthal, and the region between it and Tasermint, 
which has not yet been explored with care. 
It was his intention to start for the eastern coast 
about the end of April, or early in May, 1884; and 
during the winter of 1884-85 some members of the 
party were to remain there. | 
HUMIDITY AND CHRONOMETER RATES. 
MaAJor-GeEn. J. F. TENNANT, of her Majesty’s mint, 
Calcutta, communicated to the Royal astronom- 
ical society in November last a paper on humidity 
asa cause of variation in the rate of chronome- 
ters. He had borrowed from the government-stores 
about the end of March, 1882, a chronometer, by 
Fletcher of London, which had been some time in 
India, but had not been cleaned since its arrival, 
and was said to havea goodrate. From a gaining- 
rate of 68.5, which it preserved fairly well for about 
two months, it suddenly fell to a gaining-rate of 2s.0; 
this being the commencement of a succession of 
rather abnormal fluctuations of rate which Major 
Tennant carefully observed and recorded for about 
eighteen months. These rates were first compared 
with a plot of the published daily mean temperatures 
of the meteorological observatory, with results not 
quite satisfactory; for, though it would seem at first 
sight that the rate depends on temperature, further 
examination showed that it can do so to a moderate 
extent only, and confirmed the belief, which Major 
Tennant had from general impressions, that rate does 
not depend on temperature. The extraordinary dif- 
ferences of rate at times of nearly equal temperature 
leave no doubt that there is a periodic change of 
rate; and the cause of this, Major Tennant believes 
to be humidity. His first suspicion of this was raised 
by the sudden fall in rate of this chronometer, in 1883, 
being coincident with the first heavy rains producing 
great damp; and by the fact, also, that the same thing 
occurred the year previous, and that the whole period 
of low gaining-rate was that of the rains, while the 
lowest was the warm time at the end of the rains, when 
the soil is generally loaded with moisture. The same 
phenomenon recurred. It is, however, much more 
difficult to compare the supposed cause and effect 
without special arrangements; and, in any case, it is 
doubtful whether air-humidity could be more than 
a rough guide. 
If the oil in the arbors of the balance be hygro- 
scopic, it is easy to see that it may become more 
fluid in damp weather, the arc of oscillation will in- 
crease, the balance-vibration take longer, and the 
chronometer lose; but the momentary humidity of 
the air will not correspond to the rate, as the tem- 
perature does more or less. Major Tennant, remark- 
ing the undoubted connection in this particular case, 
suggests special experimenting in the following di- 
rections: — 
1°. Are chronometer-oils, or any of them, hygro- 
scopic ? 
SCIENCE. 
287 
2°, Can they become so by exposure to a tropical 
climate ? 
In this latter case he conceives that the climatic 
influence cannot be imitated in Europe. The effect 
of the heat, and probably the light, are very destruc- 
tive of some materials. Vulcanized india-rubber, 
for example, does not bear exposure in India, though 
it seems to answer in Europe, even in heat and 
damp. 
Lastly, in estimating the effect of humidity on a 
given chronometer, it will probably be best to use 
one of the old hair or grass hygroscopes for the hu- 
midity, placing it in the case, enclosed with the chro- 
nometer. DAvip P. Topp. 
THE GREAT COMET OF 1882. 
THIS comet is one of the most interesting that has 
appeared for a number of years, owing to its very hear 
approach to the sun-surface, and the resemblance of 
its orbit to the two great comets of 1843 and 1880. 
It was a brilliant object in the morning sky in Sep- 
tember, 1882. Calculations of the orbit have been 
made recently by Dr. Morrison, Professor Frisby, and 
Dr. Kreutz. The periods obtained are as follows: 
Dr. Morrison, 712.1 years; Professor Frisby, 795.9; Dr. 
Kreutz, 843.1. These periods are, however, somewhat 
uncertain, owing to the peculiar nature of the nucleus 
of this comet. Instead of being a single bright body, 
there appeared to be a row of small nuclei, so that it 
was a mere matter of judgment with the observer 
what part of the comet he should observe. The ob- 
servations were naturally made upon the middle of 
the row of points, and it is not possible to say with 
certainty that this corresponded to the centre of 
gravity of the comet. It is worthy of note, that 
bright comets are recorded in the year 370 B. C. and 
in A.D. 1132, both of which could be reconciled with 
the great comet of 1882 by supposing the period of 
751 years. 
THE WORK OF THE CAMBRIDGE 
ARCHAEOLOGICAL MUSEUM. 
THE trustees of the museum of American archae- 
ology and ethnology, founded by George Peabody, 
held their annual meeting on the 18th of February, 
the anniversary of the birth of the founder. The 
Hon. Robert C. Winthrop, president of the board, 
presided; and Professor Asa Gray, Dr. Henry Wheat- 
land, Mr. John C. Phillips, Mr. Samuel H. Scudder, 
and Mr. F. W. Putnam (the curator of the museum) 
were present. The Hon. Stephen Salisbury of Worces- 
ter was prevented by temporary illness from attend- 
ing, and the Hon. Theodore Lyman was unable to 
leave his duties in Congress. 
The report of the treasurer, Mr. Phillips, showed 
that the $150,000 given by Mr. Peabody is well in- 
vested. Of the income of $8,334, only $5,186.50 was 
expended on account of the museum: $3,110 be- 
longed to the building-fund, and the remaining 
$37.50 was expended on insurance. Mr. Winthrop 
