He was, however, so much annoyed by the treacherously brittle nature of the speculum metal that he abandoned its use, and betook himself to glass. He found that before he could make a good achromatic telescope it was necessary that he should calculate his curves from data depending upon the nature of the glass. He accordingly proceeded to study the optical laws of refraction, in which his knowledge of geometry and mathematics greatly helped him. And in course of time, by his rare and exquisite manipulative skill, he succeeded in constructing a four-inch refractor, or achromatic telescope, of admirable defining power.
The excellence of his first works became noised abroad.
Astronomical observers took an interest in him; and friends began to gather round him, amongst others the late Professor Phillips and the Rev. Vernon Harcourt, Dean of York. Cooke received an order for a telescope like his own; then he received other orders. At last he gave up teaching, and took to telescope making. He advanced step by step; and like a practical, thoughtful man, he invented special tools and machinery for the purpose of grinding and polishing his glasses. He opened a shop in York, and established himself as a professed maker of telescopes. He added to this the business of a general optician, his wife attending to the sale in the shop, while he himself attended to the workshop.
Such was the excellence of his work that the demand for his telescopes largely increased. They were not only better manufactured, but greatly cheaper than those which had before been in common use. Three of the London makers had before possessed a monopoly of the business; but now the trade was thrown open by the enterprise of Cooke of York. He proceeded to erect a complete factory--the Buckingham Street works. His brother took charge of the grinding and polishing of the lenses, while his sons attended to the mechanism of the workshop; but Cooke himself was the master spirit of the whole concern.
Everything that he did was good and accurate. His clocks were about the best that could be made. He carried out his clock-making business with the same zeal that he devoted to the perfection of his achromatic telescopes. His work was always first-rate. There was no scamping about it. Everything that he did was thoroughly good and honest. His 4 1/4-inch equatorials are perfect gems; and his admirable achromatics, many of them of the largest class, are known all over the world. Altogether, Thomas Cooke was a remarkable instance of the power of Self-Help.
Such was the story of his Life, as communicated by Mr. Nasmyth.
I was afterwards enabled, through the kind assistance of his widow, Mrs. Cooke, whom I saw at Saltburn, in Yorkshire, to add a few particulars to his biography.
"My husband," she said, "was the son of a working shoemaker at Pocklington, in the East Riding. He was born in 1807. His father's circumstances were so straitened that he was not able to do much for him; but he sent him to the National school, where he received some education. He remained there for about two years, and then he was put to his father's trade. But he greatly disliked shoemaking, and longed to get away from it. He liked the sun, the sky, and the open air. He was eager to be a sailor, and, having heard of the voyages of Captain Cook, he wished to go to sea. He spent his spare hours in learning navigation, that he might be a good seaman. But when he was ready to set out for Hull, the entreaties and tears of his mother prevailed on him to give up the project; and then he had to consider what he should do to maintain himself at home.
"He proceeded with his self-education, and with such small aids as he could procure, he gathered together a good deal of knowledge. He thought that he might be able to teach others.
Everybody liked him, for his diligence, his application, and his good sense. At the age of seventeen he was employed to teach the sons of the neighbouring farmers. He succeeded so well that in the following year he opened a village school at Beilby. He went on educating himself, and learnt a little of everything. He next removed his school to Kirpenbeck, near Stamford Bridge; and it was there," proceeded Mrs. Cooke, "that I got to know him, for Iwas one of his pupils."
"He first learned mathematics by buying an old volume at a bookstall, with a spare shilling. That was before he began to teach. He also got odd sheets, and read other books about geometry and mathematics, before he could buy them; for he had very little to spare. He studied and learnt as much as he could.
He was very anxious to get an insight into knowledge. He studied optics before he had any teaching. Then he tried to turn his knowledge to account. While at Kirpenbeck he made his first object-glass out of a thick tumbler bottom. He ground the glass cleverly by hand; then he got a piece of tin and soldered it together, and mounted the object-glass in it so as to form a telescope.
"He next got a situation at the Rev. Mr. Shapkley's school in Micklegate, York, where he taught mathematics. He also taught in ladies' schools in the city, and did what he could to make a little income. Our intimacy had increased, and we had arranged to get married. He was twenty-four, and I was nineteen, when we were happily united. I was then his pupil for life.
"Professor Phillips saw his first telescope, with the object-glass made out of the thick tumbler bottom, and he was so much pleased with it that my husband made it over to him. But he also got an order for another, from Mr. Gray, solicitor, more by way of encouragement than because Mr. Gray wanted it, for he was a most kind man. The object-glass was of four-inch aperture, and when mounted the defining power was found excellent. My husband was so successful with his telescopes that he went on from smaller to greater, and at length he began to think of devoting himself to optics altogether. His knowledge of mathematics had led him on, and friends were always ready to encourage him in his pursuits.
