138 
NATURE | 
[Dec. 2, 1869 
was that described by his brother before Section A of the 
British Association at Exeter. By the time these lines are 
in print the cable may possibly have been laid, but much 
depends upon the weather. When the weather is fine, it 
usually takes half a day to lay each of the shore ends of 
a cable, and the deep-sea portion is ordinarily paid out at 
the rate of five knots per hour. The time occupied in 
paying out the deep-sea portion of the cable now under 
notice should be about twenty hours in all. 
IDES VIEININ VG, TIS) Fs 
eS our first number we had to record the death of 
Thomas Graham, one of the greatest chemists of 
the century, and formerly an occupant of the chair of 
chemistry in Anderson’s Institution, Glasgow. We have 
now to announce the death of Frederick Penny, who, 
with the exception of the short interval between 1837 and 
1839, when Gregory was its occupant, has filled it with 
increasing reputation and success ever since Graham 
vacated it to go to London, thirty-two years ago. Born 
in London in 1817, he was devoted to chemistry from his 
earliest years, and studied in the Apothecaries’ Hall under 
Henry Hennell, F.R.S. It was while here that he was 
led to inquire into the combining weights of certain of the 
elements, by finding that the amount of potassic chloride 
obtained by acting upon pure potassic nitrate with excess 
of hydrochloric acid did not correspond with the quan- 
tity which theory showed should be obtained. Having 
made sure that the difference was not due to errors 
in his experiments, he ascribed it to inaccurate equivalents 
assigned to the elements. As the result of his investiga- 
tions, he showed that the equivalents current at the time 
for chlorine, nitrogen, potassium, sodium, and silver were 
not in strict accordance with experiment, and that the 
“hypothesis of all equivalents being simple multiples of 
hydrogen is no longer tenable.” [Phil. Trans. 1839. Part 
i. p. 32.] There can be no question as to the clearness of 
this paper and the value of the results obtained, and our 
interest in them is in no way diminished when we find 
that the equivalents determined by Penny agree in a very 
remarkable manner with the mean numbers published by 
Stas, and that this agreement has been pointed out by 
that chemist. [Fresenius, Zeits. ftir Annal. Chem. 1868, 
pp- 164,168. Compare Penny’s Table, Phil. Trans. 1839, i. 
Pp. 32, with Stas’s Fres. Zeits. 1868, p. 170.] 
The paper was published in January 1839, and the 
same year he was appointed to the vacant lecturership in 
Anderson’s Institution. Dr. Penny himself has had but 
recently to give an account of his struggles and successes 
in Glasgow, since settling in it thirty years ago. Recom- 
mended by Graham, he went down to a sphere of life and 
action, more strange at that time toa native of London than 
it has since become ; but he devoted himself strenuously 
to his work, and at the time of his death had won in 
Glasgow and the West of Scotland a wide reputation as 
one of the clearest and most emphatic lecturers, and one 
of the most painstaking teachers. 
LEDTPERS LO THE EDITOR 
[The Editor does not hold himself responsible for opinions expressed 
by his Correspondents. | 
Lectures to Working Men 
I HEARTILY concur in Mr, Stuart’s opinion, that the working 
men of England—speaking at least for the North—are fully 
aware of the value of Scientific Instruction in its strict sense. 
The subject has a special interest for me; as in the winter of 
1866-7, I started in this city a series of Science Lectures for the 
People, which, with the kind help of Prof. Jevons, Dr. Alcock, 
and Dr. Morgan, were undertaken for the purpose of ascertaining 
whether the working men of Manchester really appreciate the 
value of science instruction when given in a plain, but scientific 
form, illustrated with diagrams and experiments made on a scale 
such as could be seen by a large audience. The experiment 
proved highly successful. Upwards of 4,000 people attended the 
thirteen Lectures which we gave, and the class of persons present 
was exactly that for whom the lectures were designed ; whilst the 
marked attention and interest invariably exhibited by the audiences 
showed how keenly they appreciated the information they 
received, and the insight into true scientific methods which they 
obtained. 
The lecturer’s words were taken down by Mr. Pitman, and 
the lectures were each week printed and published by Mr. John 
Heywood, of Manchester, and largely sold at one penny each at 
the door of the lecture-room and elsewhere. I printed syllabuses 
of the chief points of my four lectures, and one was given to 
each person entering theroom. When I say that the subject of 
my first lecture was the explanation of the principles of the 
Indestructibility of Matter and of Energy, with a description of 
Joule’s Determination of the Mechanical Equivalent of Heat, I 
think you will see that mere amusement was not the aim; the 
same remark applies to all the other lectures, and yet Inever met 
with a more attentive and appreciative audience than these 
Manchester working men. 
Professor Jevons gave us a most excellent lecture on ‘‘ Coal, its 
Value and Importance in the Arts and Sciences ;” Dr. Alcock 
gave four capital lectures on Elementary Zoology, and Dr. Morgan 
a course of four on Elementary Physiology, a subject in which 
the greatest interest was evinced. 
We charged one penny per head for admission, and the penny 
fees did not nearly cover the necessary outlay, which was defrayed 
by some friends. Not only was the expense a difficulty, but the 
work of carrying on such a system was more than could be 
regularly and gratuitously borne by men whose strength was 
already sufficiently taxed by their own professional duties. 
Otherwise, the lectures would have certainly been continued, for 
we were all fully persuaded that no mode of commencing science 
teaching for the people is so effective as this, or so likely to ripen 
into a permanent demand for scientific education amongst the 
working classes. As a proof of this, I may add that for two 
winters a class was formed in connection with these lectures for 
regular instruction in Chemistry under an able Government science 
master—one of my pupils, who had gradually raised himself from 
the position of a common factory hand. For this instruction 
sixty working men each paid 2s. 6d. for thirteen lessons. I often 
looked in upon them, and a more hard-working and: enthusiastic 
class I never had the good fortune to see. 
If such science lectures, followed up by regular science in- 
struction, could be permanently established every winter, under 
careful and thoroughly competent teachers, in each of our great 
centres of industry, what invaluable results might not be 
accomplished! This is truly a subject worthy of the attention of 
some of our wealthy philanthropists ; if, indeed, Government 
does not take the matter up. How much better would it be to 
devote money to the establishment of such a series of science 
classes, than, as is too often the custom, to employ it for building 
an almshouse ! H. E. Roscor 
Owens College, Manchester, Noy. 23, 1869. 
Changes in Jupiter 
DurinG the months of October and November the planet 
Jupiter has presented a spectacle of singular and almost un- 
exampled beauty. The belts on the planet are more than 
usually numerous, and they display a greater variety of colours 
than I have ever yet seen ascribed to them. The equatorial belt, 
which has been for years the brightest part of the planet, is 
now not nearly so bright as the light belts to the north and 
south ; usually it has been free from markings, now it is often 
covered with markings, which resemble piled-up cumulus clouds : 
it has generally been colourless, shining with a silver-grey, or 
pearly lustre—now it is of a rich deep yellow, greatly resembling 
the colour of electrotyped gold. 
The woodcut represents Jupiter as it was seen on the night 
of the 9th of March in a reflecting telescope with a silvered glass 
mirror of 12} inches diameter. The upper part of the planet is 
the S. pole. On this portion of the disc there are three dark 
belts, while on the N. there are only two. 
The poles of the planet are ashy blue, and the darker belts 
nearest to them present a darker tint of the same colour. The 
bright belts next these are pearly-white, and shine more brilliantly 
than any other portion of the planet. The dark belts next to the 
central bright belts are coppery red. As already mentioned, the 
