Word: mirror
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...optical parts of the telescope are three-the eye-piece, the object glass, which is twelve inches in diameter and a plain mirror of eighteen inches in diameter, set in front of the object glass. Focal length is sixteen and a half feet. The telescope tube is rested permanently upon two stone piers, one near each end, and twelve feet apart. About five feet of the length of the tube projects into the observatory building and the remainder is out of doors...
...novel and most important feature of the telescope is the mirror. This is polsed or hinged so that it may be set at whatever angle is necessary for reflecting the object of study into the telescope field; but there is this strict limit of the range of observation, that the object must be at or near to meridian. For the contemplated uses of the instrument this limitation is not regarded as a disadvantage, as the meridian position of an object is always best for observation because there the atmospheric obstruction is least. By varying the angle at which the mirror...
...glass of the two telescopes is of the finest French make. The mirror is four inches thick, for any plate would probably change its shape from expansion or flexure. The telescopic tube is jointed so as to be air-tight throughout and at the eye-piece. Its material is steel plate one thirty-second inch thick. The temperature of the room does not effect its interior and no fogging of the object glass has occurred during cold nights...
...observatory is to have a new meridian photometer to measure stars of the eighth to the thirteenth magnitude. The telescopic objective is to be one foot in diameter, and the circular mirror used to reflect the stars into the telescope will weigh 75 pounds. Alvin Clark and Sons are at present making plans for the photometer...
...dressing-rooms are very convenient, and since a mirror has been hung in the hall, the girls seem to appreciate them; they do away with the bother of going to the rooms to prepare for exercise, making the operation much quicker and easier. Each room is furnished with a stool, hooks, and a locker for the suits...