A PROPOSED GREAT TELESCOPE.

Hawke's Bay Times, Issue 1530, 2 December 1873, Page 37

A PROPOSED GREAT TELESCOPE.

Mr S. 11. Mead, Jim,, in a letter to the Scientific American, speaks of constructing the telescope of the future, which shall take 15 years to build, and cost about ten millions sterling. He thus discourses of its construction and of what may result ftom it: —The unit of construction is a stationary hexagonal fragment of the great telescope lens, into which a movable heliostat mirror reflects the object observed. Each part of the lens is of the size and cost of an ordinary ten or twelve inch object glass, and is to be corrected mechanically by a local polisher. The necessary calculations may be made and verified by completing and using Mr Babbage's analytical engine, which applies the principleof the Jacquard loom to any possible computation. Supposing ourselves to be in possession of unlimited skilled labor and machinery, with sufficient funds, we select, in the far northwest, an elevation where the sky is generally clear. On its southern slope, we dig and build a tunnel pointing to the pole, 80 feet in diameter at base, and narrowing upwards for nearly a thousand feet. At the upper end of this tunnel is placed the observatory, containing the binocular and microscopic eye pieces of the great telescope, a frame to hold the

eye piece in use, and a meridian circle, for time. Outside are buried clocks in air-tight vacuous cases, and electric batteries and wires for adjusting any of the five thousand pristnoidal lenses below, and for moving their mirrors. At the lower end of the tunnel is mounted the great compound lens, and outside of- this, the mirror frame. Each mirror is driven westward, against the earth's daily movement, by a spring governor clock, keeping time with its fellows. All are controlled to follow the planets or moon, by a mercurial pendulum clock of absolute perfection. Its wearing parts are faced with boron or iridium, with black diamond bearings. This main driving clock is moved by many water batteries and its electro-magnets, in an exhausted glass case containing rarefied hydrogen aad the wires, through which overy second, the clock sends its electric beats. The flat glass heliostat mirrors are coated on their front surfaces with platiniridium from the Oregon iron sands, polished to reflect nine-tenths of the incident light. To find a star with our telescope, one has only to move a pointer forward on a

telegraphic dial, for the difference between the star's right ascension and the local sidereal time. Each mirror turns on its polar axis, moved by an endless screw, as is the type wheel of the stock printing telegraph, by its ratchet wheel and electromagnets. At another touch of an index on a second dial, indicating declination above or below the celestial equator, the star flashes into the field with overpowering brilliancy. Touch an index on a third dial, and the mirrors are all clamped and wili follow the object round and round the world, and have it yet in view at its third rising. Such a telescope could be built in fifteen years for inside of fifty millions of dollars. If every part could be kept at a uniform temperature, or compensated, it would enable us to contemplate the moon as from a distance of two miles. According to the nebular theory, as the outer planets are the oldest, the inhabitants, if such there be, must have developed a civilization far superior to ours. The chief value of such a telescope would be to assist in opening communication with theni by means of the ordinary Morse night signal flashes, so that we may learn from their experience instead of slowly evolving the arts and sciences for ourselves. Workingmen in America are. offering, subscriptions for the construction bf-a monster telescope.