Sept, 23, 1886 ] 
NATURE 
499 
solar spectrum on the same plate—the only ones worth 
anything, have also been secured by Mr. Maunder. But 
we must not build too much on this, for, as I have said 
before, these photographs have not yet been developed ; 
but if only one good one has been received, the laboratory 
work it should set going will take at least one or two years 
before the teachings of the precious record are exhausted. 
The so-called ‘measurement’ of such photographs is 
worth next to nothing. 
“ Among the records obtained on this occasion must be 
classed the disk observations, now for the first time in- 
cluded in the ordinary routine of eclipse work. The point 
of a disk observation is that an observer is by its aid able 
to observe the outlying solar appendages under the best 
conditions, so far as the sensitiveness of the eye is con- 
cerned. For ten minutes before totality the observer is 
blindfolded, and at the mo nent of the totality he is led to 
a small aperture through which, the bandage over his eyes 
having been removed, he sees a black disk some 40 feet 
away, which shuts off the moon and the brighter interior 
portion of the solar atmosphere. The eye, therefore, being 
thus shielded, is in the best position to pick up faint 
streamers extending beyond the borders of the disk, and 
to note their positions and extension. Streamers were 
thus noted at Grenada, extending far beyond the limits 
seen in the ordinary way, but the air was so saturated with 
aqueous vapour and incipient cloud, even where substantial 
clouds did not make their appearance, that the failure of 
any of the observers to see the equatorial extension ob- 
served by Prof. Newcomb in the clear sky of Wyoming, 
at an elevation of 7000 feet, in 1878, by no means proves 
that the extension was not there. The question of the 
continual existence of an extension of matter of some sort | 
or other in the plane of the sun’s equator must be held to 
be still sab judice. 
“Capt. Archer at Fantéme Island, and Capt. Maling 
at Prickly Point, made disk observations fairly accordant. 
The former had greatly improved the disk provided him 
by surrounding it with concentric rings of wire, so that 
distances from the centre could be measured with the 
greatest accuracy. 
“The records obtained by Prof. Thorpe regarding the 
intensity of the light of the corona were sufficient in 
number to suggest that when they are reduced a value will 
be obtained to be placed side by side for purposes of com- 
parison with those previously obtained in 1870 and 1878. 
In this connection it may be remarked that the darkness 
of an eclipse must not be taken as a measure of the dim- 
ness of the corona, for, if the totality be longer, more of 
the brighter portion of the solar atmosphere will be covered. 
This was certainly the darkest eclipse seen since eclipse 
expeditions have been in vogue. This shows the import- 
ance of Prof. Thorpe’s work, for if successful it will give 
us the luminous intensity per unit of surface of different 
regions of the solar atmosphere, as well as the intensity 
of the total light emitted. 
“The preceding sketch of the results obtained has of 
necessity been of the most general character. Not tillall 
the observations are published in detail, as they doubtless 
will be at no very distant date by the Royal Society, 
and not till they have been discussed by those competent 
to discuss them, can a final verdict as to their value be 
given. We have of set purpose dealt only with the con- 
clusions which lie on the surface.” 
NOTES 
THE death of Alessandro Dorna, Director of the Astronomical 
Observatory of Turin, took place on August 19 last, at the age 
of sixty-one years. 
THE annual Congress of the Sanitary Institute of Great 
Britain commenced on Tuesday in York. Sir T. Spencer Wells, 
the President, commenced his inaugural address by expressing 
the hesitancy with which he accepted the position of President 
of the Congress, a hesitancy induced by the knowledge that he 
could not presume to appear before a body of sanitary experts 
as an instructor. Having referred to questions which had been 
dealt with in regard to sanitary science by his predecessors in 
the Presidential chair, he observed that it now remained to be 
considered how sanitary improvements might be carried still 
further by the co-operation of investigators, legislators, and ad- 
ministrators. As to the work of investigation, it had hitherto 
for the most part been personal, and the waste of labour had 
been enormous. The Institute must develop into something 
grander and more powerful. The Colleges of Physicians and 
Surgeons had done much, but it was rather for individual than 
collective good, Why should we not have a College of Health ? 
The President then reviewed the work which those whom he 
called the ‘‘advanced guard of sanitary science” had accom- 
plished, in lessening the death-rates of our population, and in 
benefiting the public health by prolonging life. Much of this 
he attributed to the coincident progress made in the science and 
art of medicine and surgery. He claimed for the medical pro- 
fession a considerable share in the gain to the State of increas- 
ing numbers of more healthy subjects. We could not be far 
wrong if we put the average duration of human life in Great 
Britain half a century ago at about thirty years ; now, according 
to the healthy life table, it was forty-nine years, Formerly it 
was calculated that a twenty-third part of the population was 
constantly sick, and the products of all that labour for the time 
necessarily withdrawn. <A great deal of this sickness had been 
altogether prevented, and the duration of that which comes in 
spite of sanitation was lessened. He then dealt with the pro- 
gress which had been made, since the Sanitary Institute had 
come into existence, in the moral and physical condition of our 
population. Dealing then with the various subjects to which 
the Institute had given attention, he divided them into five 
groups: (1) those relating to the training and health of the 
population ; (2) to their social comfort and well-being ; (3) to 
the prevention of disease; (4) to the care of the sick ; and, 
lastly, those relating to the disposal of human refuse and re- 
mains. As to teaching the public on sanitary matters, it could 
never be done without elaborate organisation and legislative 
authority. 
One of the tasks undertaken by the authorities of the British 
Museum since printing has taken the place of handwriting in 
the Catalogue is the publication of certain important sections of 
the Catalogue in separate parts. Thus the entries under 
America, Cicero, Luther, London, and many others have 
already appeared. ‘The last of these is one of special scientific 
interest: it isa reprint of that part of the Catalogue which ‘is 
classified under the head Academies. The definition of 
academies for the purpose is ‘‘ Learned and Scientific Socie- 
ties.” The entries fill five parts, making a thick folio volume 
of about one thousand pages. In the great written Catalogue, 
which is well known to all readers, twenty-eight volumes 
were given to this one subject. The headings have been 
thoroughly revised throughout, and the names of a number 
of societies have been expunged, to be placed under more 
appropriate headings. Thus, agricultural societies, schools, 
political clubs, &c., which had crept into the Catalogue 
by degrees in course of time, have all been omitted. As 
it is, the total number of entries is about 32,000. ‘‘ Lon- 
don” is the longest sub-heading; it fills nearly 290 pages, 
with about 6500 entries. Paris, St. Petersburg, and Berlin 
have about 3000 entries each; Vienna and Amsterdam about 
1000, Towns are used for sub-headings, and under these are 
arranged alphabetically the names of the societies issuing the 
publications. The old sub-headings of countries have been 
abolished. Formerly the sub-headings would read thus :— 
