which I computed the hour-angle for Jupiter, and set the

instrument so that by calculation Jupiter should pass through the
field of the instrument at 1h. 25m. 15s. With my watch in my

hand, and my eye to the eye-piece, I waited for the orb. When
his glorious face appeared, almost in a direct line for the

centre of the field, I could not contain my joy, but shouted out
as loudly as I could,--greatly to the astonishment of old George

Johnson, the miller, who happened to be in the field where I had
planted my stand!

"Now, though I had obtained what I wanted--a fairly good
instrument,--still I was not quite satisfied; as I had produced

it by a fortunate chance, and not by skill alone. I therefore
set to work again on the other disc of glass, to try if I could

finish it in such a way as to excel the first one. After nearly
a year's work I found that I could only succeed in equalling it.

But then, during this time, I had removed the working of mirrors
from mere chance to a fair amount of certainty. By bringing my

mathematical knowledge to bear on the subject, I had devised a
method of testing and measuring my work which, I am happy to say,

has been fairly successful, and has enabled me to produce the
spherical, elliptic, parabolic, or hyperbolic curve in my

mirrors, with almost unvarying success. The study of the
practical working of specula and lenses has also absorbed a good

deal of my spare time during the last two years, and the work
involved has been scarcely less difficult. Altogether, I

consider this last year (1882-3) to mark the busiest period of my
life.

"It will be observed that I have only given an account of those
branches of study in which I have put to practical test the

deductions from theoretical reasoning. I am at present engaged
on the theory of the achromatic object-glass, with regard to

spherical chromatism--a subject upon which, I believe, nearly all
our text-books are silent, but one nevertheless of vital

importance to the optician. I can only proceed very slowly with
it, on account of having to grind and figure lenses for every

step of the theory, to keep myself in the right track; as mere
theorizing is apt to lead one very much astray, unless it be

checked by constant experiment. For this particular subject,
lenses must be ground firstly to spherical, and then to curves of

conic sections, so as to eliminate spherical aberration from each
lens; so that it will be observed that this subject is not

without its difficulties.
"About a month ago (September, 1883), I determined to put to the

test the statement of some of our theorists, that the surface of
a rotating fluid is either a parabola or a hyperbola. I found by

experiment that it is neither, but an approximation to the
tractrix (a modification of the catenary), if anything definite;

as indeed one, on thinking over the matter, might feel certain it
would be--the tractrix being the curve of least friction.

"In astronomy, I have really done very little beyond mere
algebraical working of the fundamental theorems, and a little

casual observation of the telescope. So far, I must own, I have
taken more pleasure in the theory and construction of the

telescope, than in its use."
Such is Samuel Lancaster's history of the growth and development

of his mind. I do not think there is anything more interesting
in the 'Pursuit of Knowledge under Difficulties.' His life has

been a gallantendeavour to win further knowledge, though too
much at the expense of a constitutionoriginallydelicate. He

pursues science with patience and determination, and wooes truth
with the ardour of a lover. Eulogy of his character would here

be unnecessary; but, if he takes due care of his health, we shall
hear more of him.[11]

More astronomers in humble life! There seems to to be no end of
them. There must be a great fascination in looking up to the

heavens, and seeing those wondrous worlds careering in the
far-off infinite. Let me look back to the names I have

introduced in this chapter of autobiography. First, there was my
worthy porter friend at Coupar Angus station, enjoying himself

with his three-inch object-glass. Then there was the shoemaker
and teacher, and eventually the first-rate maker of achromatic

instruments. Look also at the persons whom he supplied with his
best telescopes. Among them we find princes, baronets,

clergymen, professors, doctors, solicitors, manufacturers, and
inventors. Then we come to the portraitpainter, who acquired

the highest supremacy in the art of telescope making; then to Mr.
Lassell, the retired brewer, whose daughters presented his

instrument to the nation; and, lastly, to the extraordinary young
schoolmaster of Bainbridge, in Yorkshire. And now before I

conclude this last chapter, I have to relate perhaps the most
extraordinary story of all--that of another astronomer in humble

life, in the person of a slate counter at Port Penrhyn, Bangor,
North Wales.

While at Birnam, I received a letter from my old friend the Rev.
Charles Wicksteed, formerly of Leeds, calling my attention to

this case, and inclosing an extract from the letter of a young
lady, one of his correspondents at Bangor. In that letter she

said: "What you write of Mr. Christmas Evans reminds me very much
of a visit I paid a few evenings ago to an old man in Upper

Bangor. He works on the Quay, but has a very decided taste for
astronomy, his leisure time being spent in its study, with a

great part of his earnings. I went there with some friends to
see an immensetelescope, which he has made almost entirely

without aid, preparing the glasses as far as possible himself,
and sending them away merely to have their concavity changed. He

showed us all his treasures with the greatest delight, explaining
in English, but substituting Welsh when at a loss. He has

scarcely ever been at school, but has learnt English entirely
from books. Among other things he showed us were a Greek

Testament and a Hebrew Bible, both of which he can read. His
largest telescope, which is several yards long, he has named

'Jumbo,' and through it he told us he saw the snowcap on the pole
of Mars. He had another smaller telescope, made by himself, and

had a spectroscope in process of making. He is now quite old,
but his delight in his studies is still unbounded and unabated.

It seems so sad that he has had no right opportunity for
developing his talent."

Mr. Wicksteed was very much interested in the case, and called my
attention to it, that I might add the story to my repertory of

self-helping men. While at York I received a communication from
Miss Grace Ellis, the young lady in question, informing me of the

name of the astronomer--John Jones, Albert Street, Upper
Bangor--and intimating that he would be glad to see me any

evening after six. As railways have had the effect of bringing
places very close together in point of time--making of Britain,

as it were, one great town--and as the autumn was brilliant, and
the holiday season not at an end, I had no difficulty in

diverging from my journey, and taking Bangor on my way homeward.
Starting from York in the morning, and passing through Leeds,

Manchester, and Chester, I reached Bangor in the afternoon, and
had my first interview with Mr. Jones that very evening.

I found him, as Miss Grace Ellis had described, active, vigorous,
and intelligent; his stature short, his face well-formed, his

eyes keen and bright. I was first shown into his little parlour
downstairs, furnished with his books and some of his

instruments; I was then taken to his tiny room upstairs, where he
had his big reflecting telescope, by means of which he had seen,

through the chamber window, the snowcap of Mars. He is so fond
of philology that I found he had no fewer than twenty-six

dictionaries, all bought out of his own earnings. "I am fond of
all knowledge," he said--"of Reuben, Dan, and Issachar; but I

have a favourite, a Benjamin, and that is Astronomy. I would
sell all of them into Egypt, but preserve my Benjamin." His

story is briefly as follows:--
"I was born at Bryngwyn Bach, Anglesey, in 1818, and I am