SCIENCE. 
275 
John Goodricke, an English astronomer, who in 1782 
determined the period of the variability of the famous 
star Algol, thought that Tycho’s star might be the same 
as the new stars reported to have been seen in the 
years 945 and 1264. This would make the period of 
its variability between 300 and 320 years, and hence 
this star should re-appear in the latter part of the present 
century. Goodricke’s conjecture seems to be very un- 
certain, since the reports for the years 945 and 1264 
are extremely vague. It will be seen that if we as- 
sume the period of the variability of Tycho’s star to 
be 3 r s years, five such periods would carry it back to 
near the beginning of the Christian era. Astrologers 
and others have not been slow to catch at such anal- 
ogies, and to base predictions on these uncertain data ; 
and thus we have it asserted that Tycho’s star is iden- 
tical with the star of Bethlehem, and that it will re-ap- 
pear in the year 1887, with wars and social revolutions. 
Of course it is impossible to reply to such assertions. 
Wars and social revolutions are continually going on, 
and such grim predictions are as safe therefore, as it 
is to say, that to-morrow the winds will be variable, or 
that we shall have “rain in areas or snow next Jan- 
uary. The only wonder is that intelligent people are 
imposed on by such assertions. 
At the present time more than a hundred variable 
stars are known to astronomers, and every year in- 
creases their number. Many of their periods are well 
determined, but what causes the variations of light 
we do not know. The so-called new stars may be 
only extreme cases of the variable stars, and the ap- 
pearance of one is an interesting astronomical phen- 
omenon which should be carefully observed. There 
is a rich field for observation and for study. 
A. Hall. 
Washington, D.C., Nov. 29, 1880. 
NEW YORK ACADEMY OF SCIENCE. 
We direct special attention to the excellent course of 
lectures provided by the New York Academy of Sciences, 
to which non-rnembers are admitted free, on making 
application to the proper authorities. 
The lecture for Monday next, December 6th, will be 
delivered by Professor W. Boyd Dawkins, F. R. S., of 
Owens College, Manchester, England, the subject being 
“ The Man ot the Caves.” 
We understand the present will be the only opportunity 
for hearing Professor Dawkins lecture in this country on 
a subject on which he is a specialist. We anticipate 
a large attendance. 
The present efforts of the executive of the New York 
Academy of Science, under the presidency of Professor 
Newberry, to provide a course of free lectures of the 
highest order, should be fully recognized by all in- 
terested in Science and we advise those who would 
avail themselves of the opportunity to address Professor 
D. S. Martin, of 230 West Fourth street ; or Professors 
W. P. Trowbridge and Alexis A. Julien, both of Colum- 
bia College, N. Y., as these gentlemen constitute the 
Committee on Lectures. 
HISTORICAL NOTES ON GAS ILLUMINATION. 
At the present moment when the public is all impa- 
tience to see the electric light perfected for general illu- 
minating purposes, it may be interesting to note a few 
particulars descriptive of the early days of gas, when it 
struggled into existence for the same purposes. 
In looking over a few somewhat ancient scientific pa- 
pers I found much relating to the subject, and will now 
reproduce these historical facts in the order in which I 
found them. 
It appears that in the British Museum there is pre- 
served a paper (Ascough’s Cat. 4437), entitled “ Experi- 
ments Concerning the Spirit of Coals, in a Letter to the 
Hon. Mr. Boyle, by the late Rev. James Clayton, D.D., 
B. Mus.” These experiments were undertaken by him 
in consequence of his having observed that the gas, issu- 
ing from certain fissures near a coal pit at Wigan, in 
Lancashire, took fire when a burning candle was pre- 
sented to it. He therefore distilled coal, and obtained 
first “ phlegm,” afterwards a black oil, and then “ an 
inflammable spirit,” which he collected in bladders. By 
pricking these bladders he was able to ignite the gas at 
pleasure. Hence it is evident that the discovery of the 
carburetted hydrogen gas took place previous to the year 
1664. 
So states a paper, No. 66, in the Philosophical 'Journal, 
by Mr. John Webster, “ On the Discovery of the Infiam- 
mable Gas fro 7 >i Coals the date of the paper is not 
before me, but its republication, in the form I found it, 
was in 1807. 
In the Phil. Jour., No. 67, the subject is again mooted 
by a Mr. Hume, who states that in the forty-first volume of 
the Philosophical Transactions, p. 59, is a “sheet-paper,” 
which appears to have been read before the Royal So- 
ciety in January, 1739, as “A Letter to the Hon. Robert 
Boyle, from the late Rev. John Clayton. D.D., in which 
is described how the discovery originated, and also some 
of the effects produced by this gas or 1 spirit ’ of coal.” 
Mr. Hume further draws attention to the difference in 
the Christian names given to Mr. Clayton, in the first 
instance “ James ” and the second “John,” and draws 
the very probable conclusion that the same person is re- 
ferred to in both papers, and states, “ At any rate, the 
merit of this discovery can be no longer claimed by any 
living person.” 
This remark was called forth on account of the public 
papers of that day, 1808, being much taken up with the 
proposal of a Mr. Winsor to light cities with gas. It ap- 
pears that Mr. Edward Heard also obtained a patent in 
June, 1806, for “ Obtaining inflammable gas from pit coal, 
in such a state that it may be burned without producing 
any offensive smell.” 
There was money in this patent, for Mr. Winsor was 
organizing a large company, which was not to buy the 
patent, but to pay a royalty as a license for the exclusive 
right to make use of it. As usual in such'cases there was a 
great outcry, and the attempt was made to break down 
the patent by asserting that the invention was not new, 
one Nicholson taking the ground that the pateut was 
invalid, because the inflammable nature of coal gas was 
demonstrated by “ Boyle ” before 1691 ; and he further 
stated that Lord Dundonald used gas from coal to give 
light many years ago, and that a Mr. Murdock also 
put it in practice upon a large scale in 1792 and 1798, so 
that it was absurd for Mr. Winsor to claim the inven- 
tion for the public use of gas. 
To parry these attacks Mr. Winsor published a small 
pamphlet, and boldly asserted that it was true that the 
inflammability of coal gas had been long known, but that 
no one had purified gas, and thus made it fit for general 
illuminating purposes, until he took out his patent in 
1804. He also accused others, who were in the field, of 
having obtained their knowledge from him. 
Mr. Winsor had to contend against other difficulties ; 
for, at that date, the statute law of the realm prohibited 
more than five persons holding a patent as joint property, 
and it was held that as the shareholders of the proposed 
company would share the profits, they would be joint 
holders of the patent. To this Mr. Winsor replied that 
he retained the patent himself and merely sold the right 
to use it. To show the poor prospects for gas illumina- 
