he a 
Aug. 11, 1870] 
NATURE 
303 
THE FLAGSTAFF OBSERVATORY AT 
MELBOURNE 
LL earnest workers in science must often have felt the 
extreme labour attaching to a complete reduction 
of an extended series of experiments. To derive some 
portion of truth from such a series may be a compara- 
tively easy task, but to bring out the truth, the whole 
truth, and nothing but the truth, is a very difficult one. 
Yet how much more is this difficulty increased, when the 
experiments are made by Nature herself; so that while 
on the one hand the scale has become cosmical, we have, 
on the other hand, lost all control over the apparatus and 
the experimenter. Thus it happens that our progress in 
those sciences, which are strictly observational, is more 
slow than in those which are experimental, and truly we 
are yet in the infancy of Cosmical Physics. 
In Dr. Neumayer, the late director of the Flagstaff 
Observatory, Melbourne,we have a most earnest observer 
of the highest type, and those who are aware of the 
difficulties with which he had to contend, must feel 
astonished at the very great and valuable work which he 
has successfully achieved. In the volumes of his results 
now before us, we have meteorological and magnetical 
observations of lasting value.* In meteorology we have 
a very complete set of elements extending throughout the 
years 1859 to 1863, and including, besides the usual phe- 
nomena, observations of the Zodiacal light, meteors, hail- 
stones, atmospheric electricity, and the Aurora, 
Not the least interesting of these are the observations 
of the Zodiacal light, and we may here note one or two 
remarks rather puzzling to those who assign an exclusively 
celestial origin to that phenomenon. 
1859. Sept. 19.—The upper portion appeared to be 
much broader than the base. 
Sept. 24.—It did not terminate ina point, but in a 
diffused edge of considerable breadth. The axis of the 
phenomenon was decidedly not in the ecliptic, but there 
was a particularly bright line about or in the ecliptic. 
1860. March 20.—No regular column of light, but a 
broad patch of light towards W. ; sky clear. 
July 18.—A column of light much resembling the 
Zodiacal light was visible in S., 70° E. The column 
showed great change. 
August 8.—Thelower part of the phenomenon appeared 
of a rosy tint, which at times disappeared and returned. 
1861. June 29.—A most extraordinary appearance of 
light in S.E. It descended in straight, well-defined 
lines. The light was white, and better defined than the 
Zodiacal light, and it appeared to be slightly bifurcated. 
Magnets perfectly quiet during the phenomenon. 
The nautical observations form another important divi- 
sion of Dr, Neumayer’s labours. These consist of the 
logs of various vessels which agreed to work in conjunc- 
tion with the observatory, and from these logs results are 
derived of much practical benefit to the navigator, and 
of much interest to the ocean meteorologist. In them 
the usual method of dividing the ocean into five degree 
squares has been adopted. 
A system of hourly observations in meteorology and 
terrestrial magnetism was carried on day and night, 
without interruption, for five years, after which a more 
simple system of observations was organised. 
Another important task undertaken was the magnetic 
survey of the colony, in pursuing which Dr. Neumayer 
had frequently to be absent for three or four months at a 
time. The aggregate number of miles which he travelled 
over in the survey was 11,000, and the number of stations 
he examined, 239, situated at all elevations. 
But this labour—great and Herculean as it is—repre- 
sents only a portion of that which Dr. Neumayer has 
* « Discussion of the Meteorological and Macnetical Observations made at 
the Flagstaff Observatory, Melbourne,” 
“Results of the Magnetic Survey of the Colony of Victoria.” (Triibner 
and Co.) 
done, and merely denotes the work spent in obtain- 
ing raw materials. These have now to be tabulated, 
reduced, and discussed—a process not unlike that by 
which the sheaf of the reaper is made into good, 
wheaten bread. This reduction and discussion have 
been made by Dr. Neumayer in one of the volumes now 
before us, and, in obtaining his final results, the most 
approved scientific methods have been adopted. The 
magnetic observations are very completely discussed after 
the method of Sir E. Sabine, and many valuable results 
have been obtained. In particular, allusion may be made 
to a connection, traced by Dr. Neumayer, between the 
magnitude of the lunar-diurnal variation, and the moon’s 
declination, forming a paper which has been published in 
the Transactions of the Royal Society. 
These remarks would be imperfect without alluding to 
one point for which Dr. Neumayer deserves very great 
credit. While he has reduced his observations according 
to the most approved methods, he has, nevertheless, ex- 
hibited to his readers, as far as possible, the actual obser- 
vations themseives, so that in future, if other methods of 
reduction should be followed and other objects sought, we 
can fail back upon actual facts, capable of being moulded 
anew into the form required. This is a point which ought 
surely to be borne in mind in all similar discussions. 
B. STEWART 
THE MANUFACTURE OF TAR PAVEMENT * 
i N most provincial towns there are two important 
bodies of men, the paving commissioners and the 
gas directors. The one is pledged to keep the rates low, 
and the other to keep the price of gas as low as will 
enable them to provide the statutory dividend. As one 
means of ensuring a cheap supply of gas is to create a 
greater demand and obtain a better price for the residual 
products, it is of advantage to consider a subject the 
adoption of which would be advantageous to both of these 
bodies. It is not a new one, but has hitherto been a 
neglected source of revenue to gas companies, and will 
also be a great benefit to the public. That subject is tar 
pavement. In some counties, such as Yorkshire, where 
stone is as abundant as brain is said to be, tar pavement 
will receive but little attention ; but in the eastern and 
some other counties where the same conditions do not 
exist, but where York flag costs 7s. per yard laid, tar pave- 
ment is a desideratum. In such districts there is a 
scramble for pavement ; and, on account of the high 
price, unless a paving commissioner reside in the street, 
it remains unpaved. 
Tar pavement may be made of the ordinary cinder-dirt 
produced in gas-works, of shingle, or of a mixture of both. 
The material is burnt in heaps like ballast, and when hot 
is mixed with hot tar, In practice a small fire of coke is 
made on the ground, and covered with cinder-dirt or 
shingle. When this layer is hot another is added, and so 
on in succession until a large enough heap has been pro- 
vided. The tar is now boiled in an iron copper, and taken 
when hot and mixed with the hot material from the heap 
already described, in quantities of two busheis at a time, 
in about the proportion of one gallon to every bushel of 
cinder-dirt, and slightly less than a gallon for the gravel. 
It is turned over and over with the shovel until every part 
of the material has got a covering of tar. Then the whole 
is passed through a sieve with 3-in. mesh, and part of it 
through another with 4-in. mesh, and put in heaps until 
required. Indeed, it may be kept for months before being 
laid down. 
Before the pavement is laid, an edging should be pro- 
vided about 2 in. thick, and projecting 2 in. above 
the surface of the ground to be covered, which should 
* Paper lately read before the British Association of Gas Managers, by 
Mr. T. H, Methven. 
