A protracted controversy with Johann Hevelius, in which Hooke urged the advantages of telescopic over plain sights, brought him little but discredit.
In other factories the cells are arranged in lines and are charged from the slicer by suitable telescopic pipes or other convenient means.
This was done in 1612 by Christoph Scheiner, who fully described his method of solar observation in the Rosa Ursina (1630), demonstrating very clearly and practically the advantages and disadvantages of using the camera, without a lens, with a single convex lens, and with a telescopic combination of convex object-glass and concave enlarging lens, the last arrangement being mounted with an adjustable screen or tablet on an equatorial stand.
Also several optical problems relating to lenses of various forms and their combinations for telescopic projection, rules for finding foci, &c. He does not, however, mention the camera obscura as an instrument in use, but in John Harris's Lexicon Technicum (1704) we find that the camera obscura with the arrangement called the "scioptric ball," and known as scioptricks, was on sale in London, and after this must have been in common use as a sketching instrument or as a show.
The smallest and most numerous class are the telescopic meteors invisible to the naked eye.
It is computed that twenty millions of meteors enter the atmosphere every day and would be visible to unassisted vision in the absence of sunlight, moonlight and clouds, while if telescopic meteors are included the number will be increased twentyfold.
The shaft is lined with a cylinder of wrought iron, within which a tubular chamber, provided with doors above and below, known as an P g air-lock, is fitted by a telescopic joint, which is tightly sinkin packed so as to close the top of the shaft air-tight.
Made until the introduction of Scott's telescopic sight.
Other advantages are those common to all telescopic sights.
9.-Scott'S Telescopic Sight.
The introduction of trunnionless guns recoiling axially through a fixed cradle enabled sights to be attached to the non-recoil parts of the mounting, so that the necessity of removing a delicate telescopic sight every round disappeared, and Q?'
Continuous laying and telescopic sights became possible.
- a, Microcodon clavus, showing corona, lateral antennae and jointed foot; b, Rhinops vitrea, corona from below, showing proboscidiform extension containing eyes; c, Philodina megalotrocha; d, head of Rotifer macroceros, postero-ventral view, showing lobes of corona, and antero-dorsal median antenna, telescopic with setae; e, Rotifer (Actinurus) neptunius, showing head with retracted corona, and protruded dorsal proboscis bearing median antenna, and telescopic foot with toes and spurs; f.
Bdelloidaceae; foot with two toes and accessory spurs or a simple perforated disk; body telescopic at either end, with an antero-dorsal proboscis ending in a ciliate cup and bearing the proximal antenna; corona usually bilobed, very wheel-like.
1) the upper prism is supported above the telescopic system on a flat strip of metal which can be slid through side supports on the body of the periscope.
A steel telescopic mast and upper and lower optical systems which are attached to it.
The telescopic mast is carried in trunnions on the carriage, and travels closed and in a horizontal position.
The telescopic mast consists of 8 tubes.
To re- duce resistance, these cupolas were made telescopic in the French submarines "Gymnote "and the " Gustave Zede, " but the arrangement proved unsatisfactory.
When the larvae are disturbed the similarity is produced with startling suddenness by the telescopic contraction of the anterior segments in such a manner as to suggest a triangular, pointed head with two large dorsal eyes.
Six months later, the indefatigable astronomer started for Danzig to set at rest a dispute of long standing between Hooke and Hevelius as to the respective merits of plain or telescopic sights; and towards the end of 1680 he proceeded on a continental tour.
The subsequent history of the development of the art of manufacturing glass disks for telescopic objectives will be found in the article Glass: § Optical.
This yields a very much smaller field of view, but it is very valuable for viewing feeble telescopic objects.
Far within the limit to which telescopic vision can extend binary systems are now being found by the spectroscope.
These systems appear as a connecting link between short-period variable stars on the one hand and telescopic double stars on the other.
The great cluster in Hercules (Messier 13), on the other hand, requires the highest telescopic power for its complete resolution into stars.
Actually we know that the intrinsic brightness varies very greatly, so that each increase of telescopic power not The table, which is based on over 130,000 stars, shows that along the galactic circle the stars are scattered nearly three times more thickly than at the north and south poles of the Galaxy.
As he himself wrote, "the most worthless book of a bygone day is a record worthy of preservation; like a telescopic star, its obscurity may render it unavailable for most purposes; but it serves, in hands which know how to use it, to determine the places of more important bodies."
With this method it is necessary that the rake should enter and discharge several times before the retort is clear, and thus the use of a telescopic ram worked by hydraulic power, which pushes the coke before it and discharges it at the other end, is an advantage.
A simple bell inverted in a tank of water, or may be constructed on the telescopic principle, in which case much ground space is saved, as a holder of much greater capacity can be contained in the same-sized tank.
The telescopic form consists of two or more lifts which slide in one another, and may be described as a single lift holder encircled by other cylinders of slightly larger diameter, but of about the same length.
He perfected the art of pre-telescopic observation.
Galileo was nevertheless by far the ablest and most versatile of these early telescopic observers.
1691), telescopic sights (so-called) by Jean Picard (1620-1682), who simultaneously introduced the astronomical use of pendulumclocks, constructed by Huygens eleven years previously.
The surface of the moon has been a subject of careful telescopic study from the time of Galileo.
The work of drawing up a detailed description of the lunar surface, and laying its features down on maps, has from time to time occupied telescopic observers.
- No evidence of life on the moon has ever been brought out by the minutest telescopic scrutiny, nor does life seem possible in the absence of air and water.