guly 8, 1886] 
NATURE 
225 
picking up food for them, calling them together on the approach 
of danger, and even ‘‘brooding” them at night. A case was 
communicated to him a few years since by Dr. James Gale, in 
which a turkey cock incubated six fowl’s eggs during the whole 
period, successfully producing three chickens, and continuing to 
treat them with all the care of a hen. The hen turkey with 
which he had been mated was unfortunate in her brood, and 
this circumstance appears to have impelled him to take possession 
of the fowl’s eggs. Besides the fact that in a considerable 
number of species the male not only takes his turn at incubation, 
but continues, equally with the female, to feed the young after 
they have left the nest, we have the case of the male emu, who 
performs the task of incubation alone. The male ostrich, too, 
as observed in a semi-domestic state, undertakes a large, and 
sometimes it would seem the entire, share of nidification. When 
the pair of Apterix in the Zoological Gardens nested, the male 
‘alone sat assiduously during fifteen weeks on the two eggs, 
which, however, proved infertile. A correspondent from Melks- 
ham also records a case in which a bantam cock brought up a 
brood of chickens, the mother having died when they were two 
days old. Mr, Hyde Clarke quotes instances of similar care 
bestowed by male dogs and cats in Turkey on the young. 
THE curious case of the emu is described in a letter from Mr. 
Alfred Bennett, who had an opportunity of watching the habits 
of this bird, which was, during several seasons, successfully bred 
by his father in Surrey. The hen bird, says Mr. Bennett, begins 
to lay about the end of October or beginning of November, 
and as each brood consists of twenty eggs or more, laid at inter- 
vals of two days, the process takes about six weeks. Before it 
is completed, the cock bird begins to sit. The eggs laid subse- 
quently are deposited by the hen by the side of her mate, who 
puts out his foot and draws them under him. As soon as the 
eggs begin to hatch it is necessary to isolate the hen, as she 
fights furiously with her mate, and would to all appearance kill 
the chicks if she were allowed to get at them. The whole of 
the tending of the young is performed by the male bird. 
AN opah, or king-fish (Zeus Juna), which is an exceed- 
ingly rare fish, was recently captured off the Shetland Islands 
and brought to the Colonial and Indian Exhibition for inspec- 
tion. The specimen, which is in perfect condition, measures 
‘about 5 feet in length, and weighs 160 pounds, The colours of 
the sides and back are dark green intermingled with gold and 
purple, while the irides are red. The opah seems to possess 
peculiar migratory propensities, -being found at various parts, 
even in Eastern seas. The habits of this fish seem to be little 
known, but Mr. W. August Carter, of the Colonial and Indian 
Exhibition, states that, according to inquiries and investigations 
he has made, the opah varies its diet according to the locality it 
inhabits, and that when visiting the British Islands it feeds 
chiefly upon herrings and cuttlefish. 
In one of the Courts of the Colonial and Indian Exhibition 
is a very fine raven, presented by the Maclaine of Lochbuie. 
This bird, on account of its sagacity, creates much amusement 
and interest amongst visitors. On being fed it :partakes of so 
much of the food as it requires, then hides the remainder in 
certain parts of its habitat beneath pieces of paper and other 
articles that happen to be about. As many as four hiding- 
places are made use of by the raven for storing its food, which 
it exhumes when desirous of feeding. It is a curious fact that 
the raven only resorts to such stratagems when being watched 
by the public, at other times this sagacious bird consumes its 
meals in their entirety at one time. 
THE additions to the Zoological Society’s Gardens during the 
past week include a Bonnet Monkey (JJacacus sinicus) from 
India, presented by Mr. Albert Thorne; a Macaque Monkey 
(Macazus cynomolgus) from India, presented by Mr. S. R. 
Hicks ; a Prairie Wolf (Canis Jatrans 2 ) from Winnipeg, pre- 
sented by Mr. Gerald F. Talbot ; a Common Fox ( Cants vulpes), 
British, presented by Mr. A. Browning Priestley ; a Brown Bear 
(Ursus arctos) from Asia, presented by Capt. Asher Smith ; a 
Stein-bok Antelope (Meotragus tragulus) from South Africa, 
presented by Mr. W. J. Robertson; two Violaceous Night 
Herons (Nycticorax violaceus) from South America, presented 
by Dr. A. Boon, F.R.C.S. ; a Mona Monkey (Cercopithecus 
mona) from West Africa, a Grey Squirrel (Scizeras cinereus) 
from North America, a Greater White-crested Cockatoo (Cacatua 
cristata) from Moluccas, deposited ; six Sousliks (Spermo- 
philus ), five American Flying Squirrels (Sczauroplerus 
volucella) from North America, two Glass Snakes (Pseudopus 
pallasi) from Dalmatia, purchased ; two Mule Deer (Cariacus 
macrotis? 9), a Yak (Puephagus grunniens 2), four Long- 
fronted Gerbilles (Gerdidlus. longifrons), bred in the Gardens. 
OUR ASTRONOMICAL COLUMN 
METHOD OF CORRECTING FOR DIFFERENTIAL REFRACTION 
IN DECLINATION.—Mr. McNeill, of the College of New Jersey, 
Princeton, has published in the Astronomische Nachrichten, 
No. 2735, a method of correcting micrometer observations for 
refraction which was devised originally for the diagonal-square 
micrometer, but is applicable also to the ring micrometer and 
others of the same class. In.this method the correction to the 
difference of declination is not determined separately, but the 
true difference is directly determined, the corrections being 
applied to the logarithms in the course of the computation. Mr. 
McNeill shows that if we apply the number given by 
Mnx(tan® ¢ sin? g + 1) 
to the logarithm of the half chord traversed by the star, and 
the corresponding number deduced from ’ 
Mx(tan? ¢ cos? g + 1) 
to the logarithm of the apparent distance, measured on a circle 
of declination, from the point of reference in the micrometer, the 
result obtained will be the true distance corrected for refraction. 
In the above expressions J7 is the modulus of the common 
system of logarithms, « the constant of differential refraction, 
¢ the true zenith distance, and g the parallactic angle. It is 
then only necessary to tabulate the expression 
Mx{tan® ¢ cos*(p — g) + 1} 
with arguments 4 — g and G adding subsidiary tables giving 
barometer and thermometer factors, in order to obtain the quan- 
tities required (by making / alternately = 99° and = 0°) to correct 
the micrometer observations for differential refraction in declina- 
tion. This Mr. McNeill has done, and his tables will doubtless 
be of much use to observers using the class of micrometer to 
which the method is applicable. 
New Minor PLANET.—A new minor planet, No. 259, was 
discovered by Prof. C. H. F. Peters, Clinton, New York, on 
June 28. Minor planet No. 253 has been named Mathilde. 
ASTRONOMICAL PHENOMENA FOR THE 
WEEK 1886 FULY 11-17 
( OR the reckoning of time the civil day, commencing at 
Greenwich mean midnight, counting the hours on to 24, 
is here employed.) 
At Greenwich on Fuly 11 
Sun rises, 3h. 58m. ; souths, 12h, 5m, 12°6s. ; sets, 20h. 12m. ; 
decl. on meridian, 22° 6’ N.: Sidereal Time at Sunset, 
15h. 3om. 
Moon (three days after First Quarter) rises, 15h. 49m. ; souths, 
2oh. 38m. ; sets, th. 22m.”  decl. on meridian, 15° 14’ S. 
Planet Rises Souths Sets Deel. on meridian + 
h. m. eet: h. m. ey 
Mercury ... 6 17 TSU Secs 2025) 17 ON. 
Venus... Sy beg GC) Eee oro, 4/4 a PO CIN 
Marsa) ac. Tr 88 72a ee Ze GOs ceo Ke SONS 
piters.. .... TONSt 16: 42) ~-.5..8 22053 I 22N. 
Satin. <. 3 30) T1-39)_ <4: 10148 222 baie 
* Indicates that the setting is that of the following morning. 
