2, looks as though composed of a number of segments, gradually decreasing in size from base to tip like the joints of a telescope, instead of tapering gradually and evenly from one extremity to the other.
Before the invention of the telescope the accuracy of astronomical observations was necessarily limited by the angle that could be distinguished by the naked eye.
At the focus of his telescope he placed fine silver wires at right angles to each other, which, by their intersection, formed a network of small squares.
This angle, therefore, divided by the magnifying power of the telescope gives the real angular distance of the centres of a double star.
' So far as we can ascertain, the first telescope of large size driven by clockwork was the 9-in.
The instrumental equipment of that observatory was somewhat antiquated, his largest telescope being a small refractor of 73 lines aperture, but he selected a line of work to suit the instruments at his disposal, observing nebulae and variable stars and keeping a watch on comets and new planets.
He certainly describes a method of constructing a telescope, but not so as to lead one to conclude that he was in possession of that instrument.
To telescope the jars for the next blow coming up. A skilful driller never allows his jars to strike on the downstroke, they are only used to jar down when the tools stick on some obstruction in the well before reaching the bottom, and in fishing operations.
The planets in question appeared in the telescope as star-like objects which could be compared with the stars with much greater accuracy than a planetary disk like that of Mars, the apparent form of which was changed by its varying phase, due to the different directions of the sun's illumination.
The efficiency of a telescope is of course intimately connected with the size of the disk by which it represents a mathematical point.
He fetched a small but powerful telescope, which had been in his satchel, and by its aid the little girl clearly saw the opening.
A telescope is like a very strong eye.
If I wished a boy to know something about the arts and sciences, for instance, I would not pursue the common course, which is merely to send him into the neighborhood of some professor, where anything is professed and practised but the art of life;--to survey the world through a telescope or a microscope, and never with his natural eye; to study chemistry, and not learn how his bread is made, or mechanics, and not learn how it is earned; to discover new satellites to Neptune, and not detect the motes in his eyes, or to what vagabond he is a satellite himself; or to be devoured by the monsters that swarm all around him, while contemplating the monsters in a drop of vinegar.
At a mute sign from him, a telescope was handed him which he rested on the back of a happy page who had run up to him, and he gazed at the opposite bank.
He had equipped himself with a mental telescope and looked into remote space, where petty worldliness hiding itself in misty distance had seemed to him great and infinite merely because it was not clearly seen.
Now, however, he had learned to see the great, eternal, and infinite in everything, and therefore--to see it and enjoy its contemplation--he naturally threw away the telescope through which he had till now gazed over men's heads, and gladly regarded the ever-changing, eternally great, unfathomable, and infinite life around him.