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Men of Invention and Industry-Part52_Samuel Smiles(1812-1904)_English Literature(文学名著)-第2页

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preceding month I had read up the first three subjects, but,

being pressed for time, I gave up the idea of taking



physiography. However, on the last night of the examinations, I

had some conversation with one of the students as to the subjects



required for physiography. He said, 'You want a little knowledge

of everything in a scientific way, and nothing much of anything.'



I determined to try, for 'nothing much of anything' suited me

exactly. I rose early next morning, and as soon as the shops



were open I went and bought a book on the subject, 'Outlines of

Physiography,' by W. Lawson, F.R.G.S. I read it all day, and at



night sat for the examination. The results of my examinations

were, failure in mathematics, but second class advanced grade



certificates in all the others. I do not attach any credit to

passing in physiography, but merely relate the circumstance as



curiously showing what can be done by a good 'cram.'

"The failure in mathematics caused me to take the subject 'by the



horns,' to see what I could do with it. I began by going over

quadratic equations, and I gradually solved the whole of those



given in Todhunter's larger 'Algebra.' Then I re-read the

progressions, permutations, combinations; the binomial theorem,



with indices and surds; the logarithmic theorem and series,

converging and diverging. I got Todhunter's larger 'Plane



Trigonometry,' and read it, with the theorems contained in it;

then his 'Spherical Trigonometry;' his 'Analytical Geometry, of



Two Dimensions,' and 'Conics.' I next obtained De Morgan's

'Differential and Integral Calculus,' then Woolhouse's, and



lastly, Todhunter's. I found this department of mathematics

difficult and perplexing to the last degree; but I mastered it



sufficiently to turn it to some account. This last mathematical

course represents eighteen months of hard work, and I often sat



up the whole night through. One result of the application was a

permanent injury to my sight.



"Wanting some object on which to apply my newly-acquired

mathematical knowledge, I determined to construct an astronomical



telescope. I got Airy's 'Geometrical Optics,' and read it

through. Then I searched through all my English Mechanic (a



scientific paper that I take), and prepared for my work by

reading all the literature on the subject that I could obtain. I



bought two discs of glass, of 6 1/2 inches diameter, and began to

grind them to a spherical curve 12 feet radius. I got them



hollowed out, but failed in fining them through lack of skill.

This occurred six times in succession; but at the seventh time



the polish came up beautifully, with scarcely a scratch upon the

surface. Stopping my work one night, and it being starlight, I



thought I would try the mirror on a star. I had a wooden frame

ready for the purpose, which the carpenter had made for me.



Judge of my surprise and delight when I found that the star disc

enlarged nearly in the same manner from each side of the focal



point, thus making it extremelyprobable that I had accidentally

hit on a near approach to the parabola in the curve of my mirror.



And such proved to be the case. I have the mirror still, and its

performance is very good indeed.



"I went no further with this mirror, for fear or spoiling it. It

is very slightly grey in the centre, but not sufficiently so as



to materiallyinjure its performance. I mounted it in a wooden

tube, placed it on a wooden stand, and used it for a time thus



mounted; but getting disgusted with the tremor and inconvenience

I had to put up with, I resolved to construct for it an iron



equatorial stand. I made my patterns, got them cast, turned and

fitted them myself, grinding all the working parts together with



emery and oil, and fitted a tangent-screw motion to drive the

instrument in right ascension. Now I found the instrument a



pleasure to use; and I determined to add to it divided circles,

and to accuratelyadjust it to the meridian. I made my circles



of well-seasoned mahogany, with slips of paper on their edges,

dividing them with my drawinginstruments, and varnishing them to



keep out the wet. I shall never forget that sunny afternoon upon




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