May 23, 1884.] 
shire, which drained into the river Thame, from 
which Birmingham draws its water-supply; yet Bir- 
mingham escaped. When there were two thousand 
eases of cholera in Newcastle-upon-Tyne, and the 
water at Tynemouth was so bad that it was sold in 
cans with flannel tied over the nozzles to keep the 
impurities back, not a single case of cholera occurred 
in Tynemouth. In the Crimea the Sardinian contin- 
gent of the army was stationed on a hill, and their 
water-supply was drawn from a large Prussian foun- 
tain in the oolitic rock; yet, of the sixteen thousand 
men, a thousand died from cholera in the first month. 
When he came back to England, he heard Dr. Snow 
explaining the theory that cholera-polluted water 
was necessary to the production of cholera; and he 
then said to him, that he must be mistaken, because 
he had seen, on the largest possible scale, that it was 
not a fact, and, whatever might produce cholera, he 
was satisfied that it could not be imputed in all cases 
solely to impure water. 
— Appendix No. 7 of the coast-survey report for 
1883 is a ‘ Table of depths for harbors on the coasts 
of the United States,’ prepared in outline by Com- 
mander Lull, and expanded by Messrs. Bradford and 
Parsons. The harbors are arranged in order along 
the coast from Maine to Texas, and from California 
to Alaska; and for every one the depth of water is 
given for the various bars, channels, and anchorages 
at high and low water of mean and of spring tides. 
This occupies one hundred pages, and is followed by 
an index of twenty-four more, making a work of 
great thoroughness, that must prove of high value 
to all of our coasting-vessels. A brief introductory 
mention of the tides states, that along our eastern 
coast to St. Augustine, Fla., the tides show no diurnal 
inequality, the two tidal waves of a single day being 
practically equal in range. On the Pacific coast the 
tides are of the more normal type, showing a diurnal 
inequality in height of flood, that becomes most ap- 
parent when the moon is farthest north or south of 
the equator, and disappears when it is on the equator. 
This is also characteristic of the peninsula of Florida; 
but along the northern coast of the Gulf of Mexico, 
to the Rio Grande, there is but one tide in each lunar 
day, and that is of small range, and disappears when 
the moon is on the equator. ‘ Wind tides’ are here 
very marked, especially with on or off shore winds 
that blow for several days. The range of tide can be 
closely determined from the harbor tables. 
— The report of Admiral Mouchez, director of the 
Paris observatory, was presented to the council ata 
recent meeting. The number of meridian observa- 
tions made in 1883 amounted to the number of 23,830, 
five times the largest number made at any other 
establishment. A new fifteen-inch telescope was com- 
pleted during the year, and with it one of the satel- 
lites of Mars was observed during the opposition of 
January. After the reading of the report, there was 
a special discussion respecting the removal of the 
principal instruments of the observatory to a position 
outside the city of Paris. This project has met with 
much opposition in the academy and elsewhere; but 
the observatory feels obliged to urge it, from the 
SCIENCE. 
641 
impossibility of finding a good foundation for large 
instruments. A piece of ground was purchased from 
the city a few years ago, on which to mount the great 
telescope of twenty-nine inches aperture, which is 
now in course of construction. The whole region is, 
however, so mined by the catacombs, that no good 
foundation can be secured; and it is considered abso- 
lutely necessary to mount it outside the city. It is 
considered that the grounds now owned by the obser- 
vatory could be sold for a sum sufficient to found a 
new establishment. 
—Mr. Arthur F. Gray has earned the thanks of 
conchologists by preparing, ina neat octavo of twelve 
pages, a complete list of the scientific papers of 
Thomas Bland. The works of this veteran and phil- 
osophical student of the Mollusca extend over the 
period of thirty years subsequent to 1852, and are 
seventy-two in number. Several were published 
jointly with Mr. W. G. Binney, and the series is one 
of which any naturalist might well be proud. We 
trust Mr. Bland may be spared to enlarge it in- 
definitely. 
— The immense work of Mr. Elisée Reclus, the 
Nouvelle géographie universelle, begun in 1874, has 
now reached its ninth volume. The subscribers have 
received their promised instalments regularly, and 
without fail. ‘The last volume deals with south- 
western Asia. The Athenaeum says, ‘‘ That one man 
should have been able to do so large an amount of 
work, is matter for surprise; and that he should have 
done it so well, is almost phenomenal. 
— Lieut. E. K. Moore, in a paper reprinted from 
No. 29 of the Proceedings of the U.S. naval insti- 
tute, has. given a detailed description of the method 
of testing chronometers at the Naval observatory. 
A small ‘temperature-room’ was built with double 
walls, the space between the walls being filled with 
sawdust. This room is heated by the circulation 
of hot water, and is cooled by ice in a refrigerator 
beneath the flooring, when a temperature below that 
of the outside atmosphere is required. The heating- 
apparatus, which is in a room adjoining the tem- 
perature-room, consists of a small copper boiler, 
under which are two Bunsen burners. The boiler 
is fed from a tank overhead. In the gas-pipe sup- 
plying the burners, there is a spring valve, operated 
by the armature of an electro-magnet. Two minute 
gas-jets serve to light the larger burners when this 
valve is opened. The electro-magnet is in circuit 
with a mercurial thermostat, which is so adjusted, 
that, when the mercury in the tube of the ther- 
mostat is at or above a height corresponding to the 
temperature at which it is desired to keep the room, 
the circuit is closed, and the gas is cut off from the 
burners; but, if the mercury falls below this point, 
electric contact is broken, the valve is opened, and 
the water heated and caused to circulate in the pipes 
which pass around the room and return to the boiler. 
This automatic arrangement has been found to keep 
the temperature within a range of two degrees. 
Some time during the cooler months of their trial, 
the chronometers which are to be tested are placed 
