Fan. 27, 1870] 
NATURE 
339 
half-minute, so as to ascertain the time to a second, a special 
arrangement, called a spring vemontoire, has been added, by 
means of which the wheels of the clock are detained for thirty 
seconds and escape at the half-minute, allowing the weight to 
move the hands over half a minute’s space, and wind up a small 
clock-spring in the spindle, which revolyes in two minutes. This 
keeps the pendulum and the escapement going while the rest of 
the works are held back. The following is a technical descrip- 
tion of this vemontotre:—‘‘The wheel in the spindle, which 
revolves once in five minutes, drives a second pinion with eight 
teeth, the spindle of which projects through the back of the 
clock frame, and carries a little cylinder with two notches at the 
end, one broad and shallow, the other narrow and deep. At the 
end of the vemonfoire arms are two steel projections, one of 
which passes through the broad notch and the other through the 
narrow one. As the two-minute spindle revolves, with the 
notched cylinder, it brings a notch in a right position to let one 
of the arm projections through every half-minute, allowing the 
train to move the hands, and wind up the small spring. To 
effect this the pinion with sixteen leaves is loose on the two- 
minute spindle, and is only attached to one end of the spring, 
The clock is also supplied with Denison’s double three-legged 
gravity escapement. 
Tue Mount Washington Railway, which ascends the White 
Mountains, New Hampshire, U.S., is about three miles in length, 
the average gradient being a little more than 1 in 4, which is in- 
creased in some places to the extraordinary extent of 1 in 3. The 
engine draws itself up the line by means of a ‘‘ pinion,” which 
works into a strong ‘frack” fixed between the rails, and the 
ascent of three miles is completed in about one hour. 
M. Monn, Director of the Observatory of Christiania, has 
recently surveyed the w¢vé field of Fostedalsbroen, which 
occupies 750 square kilometres. He finds that it feeds twenty- 
two glaciers of the first order and more than 200 smaller ones. 
The zé is seventy kilometres from the sea. 
Messrs. BELL AND DALpy have just issued the first part of 
a work bearing the title ‘‘ Natural Phenomena and Chronology 
of the Seasons,” and containing a chronological register of the 
remarkable frosts, droughts, thunderstorms, gales, floods, 
earthquakes, &c. which have occurred in the British Isles since 
A.D. 220. The author, Mr. E. J. Lowe, F.R.S., the well- 
known meteorologist, wishes it to be understood that his chief 
object in publishing what is confessedly a very imperfect record 
is to call attention to the subject, and elicit further information 
for a more extensive work, embracing the more remarkable 
natural phenomena of foreign countries. The compilation of a 
catalogue of this nature, if it is to be of any real benefit to 
science, involves an enormous amount of labour and much 
critical skill. The original authorities for the phenomena 
recorded should, in each case, be referred to so precisely that 
the quotations may be readily verified. It is hardly satisfactory 
to see the Preston Herald quoted in support of the assertion 
that 1,500 houses were unroofed and destroyed in London, in 
the year 944. 
Mr. JoHN H. MARTIN, secretary to the Maidstone and Mid- 
Kent Natural History Society, has just brought out the first 
number of a new publication, ‘* Microscopic Objects figured and 
described,” containing 16 wood-cuts and short descriptions of 
vegetable objects, from the yeast-plant to the spiral-vascular 
tissue from garden rhubarb. The work is intended, when com- 
plete, to contain about 200 figures, all of them original, to be 
issued in monthly numbers. It is proposed to commence with 
the primary forms of vegetable life, and to proceed onwards 
through the tissues to the woody structures of the Exogens and 
Endogens, next descending to the Acrogens, and so passing to 
the extreme limits of vegetable life, as the Desmidiz, &c., thence 
to the lower forms of animal life, the Infusoria, and on through 
the Radiata to the Insects, which will be drawn and described in 
their various orders, and the minute organs figured separately. 
THE Architect states that Lieutenant Cole, R.A., and three 
sappers, sent out by the Secretary of State for India to take casts 
of the Sanchi Tope, have arrived in Calcutta. For the benefit 
of those of our readers who have not had the privilege of seeing 
Mr. Fergusson’s magnificent work ‘‘On Tree and Serpent 
Worship,” we may mention that the Sanchi Tope, a monument 
of very high antiquity, is surrounded by walls and gateways 
covered with elaborate sculptured-decorations of the greatest 
interest to the student of the early history of the human 
race, 
THE Zield of Saturday last contains some interesting notes on 
special agricultural training-schools in France, Germany, and 
Switzerland. At Riitte in the Canton of Berne, and at Santhoven 
in Bayaria, particular attention is given to the theory and practice 
of dairy operations, and the general treatment of cow stock. 
The school of Lézardeau, on the estate of Count Conédic, in the 
Department of Finisterre, offers special facilities for the study of 
draining and irrigation. In this school there is a technical library, 
amuseum, acollection of meteorological instruments, a laboratory, 
and tools of all descriptions. The general course of study 
includes elementary mechanics, agricultural chemistry and botany, 
the pruning and grafting of fruit-trees, the making of roads, and 
other practical knowledge. At Gértz, in Austria, is a special 
institution for silkworm culture, supporting a journal exclusively 
devoted to that branch of industry. The dtAena@um states that 
the Ottoman Government is giving its support to a project of 
M. Netter, of Constantinople, to found an agricultural school for 
Jews in Palestine. 
We have been requested to notify that the following premiums 
haye been placed at the disposal of the Council of the Society 
for the Encouragement of Arts, Manufactures, and Commerce, 
for the term of seven years, by M. Septimus Piesse :—1. 
A premium of £5, for one pound of Otto of Bergamot, of 
the value of 16s. or more in the London market, being the pro- 
duce of plants (Citrus dergamia) grown in Australia, New 
Zealand, Natal, any of the British West India Islands, or any 
other British Colony or Dependency. 2. A premium of £5, for 
one ounce of Otto of Roses, of the value of 20s. or more in the 
London market, being the produce of any variety of roses grown 
together in one plantation in Australia, New Zealand, Natal, 
any of the British West India Islands, or any other British 
Colony or Dependency. 3. A premium of £10, for a canister of 
Enflowered Butter or Fat, so scented with any kind or sort of 
flower, either by infusion or enfleurage, or by means of these 
processes jointly, of the weight of 3 lbs. or more, and of the 
value of 65. per lb. in London. The said butter or fat to be 
enflowered or infused with flowers grown for the purpose 
in Australia, New Zealand, Natal, any of the British West 
India Islands, or any other British Colony or Dependency. 
ON HAZE AND DUST 
OLAR light in passing through a dark room reveals its track 
by illuminating the dust floating in the air. ‘* The sun,” 
says Daniel Culverwell, ‘‘discovers atomes, though they be 
invisible by candle-light, and makes them dance naked in his 
beams.” 
In my researches on the decomposition of vapours by light, I 
was compelled to remove these ‘‘atomes” and this dust. It was 
essential that the space containing the vapours should embrace no 
visible thing ; that no substance capable of scattering the light 
in the slightest sensible degree should, at the outset of an experi- 
ment, be found in the ‘‘experimental tube” traversed by the 
luminous beam. 
For a long time I was troubled by the appearance there of 
floating dust, which, though invisible in diffuse daylight, was at 
