The polishing of the mirror, which was begun early in 1897 and was not completed until last' autumn, was an exceedingly dvlicae piece of work, the value of the telescope depending entirely on the absolute flatness of the reflecting surface, An examination made by M. Loewy, Ditector of the Paris Observatory, showed that the work, w entrusted to M. P. Guutier of Paris, has been carried out with complete success. The great dise of glass was fixed in a circular iron frame and a steel polisher, fed with the finest emery powder, was Worked slowly backward and forward over the glass, As the slightest overheating of any part of the surface would cause fliws and irregularities, the polishing machine was never operated for more than a minute at a time and. the mirror was then left alone for an hour before another minute's polishing could be attempted, The utmost care had to be taken to prevent any moisture finding its way on to the mirror. Even the place the bare hand on.the ylass for a few was found to eauso'an appreciable swell of the surface and necessitate several days' work to remove the irregularity, Lhe whole process was carried out in" secluded corner, shut off by double dors from the rest of the workshop, and kept in a dim religious light appropriate to. an inmate destined to commune with the hea and reveal their secrets to mankind. From time to time the mirror was tested by projecting on to its surface " min beam of light through a hole ina screen, and the reflection of this artificial star was examined through a small telescope of high magnifying power. Absolute plai was shown bya clearly defined im surrounded by rings, alternately light and dark and increasing in diameter portion to their distance from the image the surface happened to be concave the point of impact of the beam of light, the image was flattened along its verted diameter the inverse result being produced the case of convexity, Then the polisher came into play again, until with infinite patience the necessary perfection was reached.
The polishing of the two g lenses, alo entrusted to M. Gautier, was mere children's play in comparison with the mirror, Nevertheless, special machinery had to be constructed to secure absolute correctness of convexity. It may be remarked en passant that the casting of large pieces of glass is one of the few depart ments of industry in which the United States have not otitstripped the Od World. Pho lenses of all the big American tele-Scopes were cast either by Cimuee of Birmingham or Feil of Paris. The 30 crown glass dis2s for the instrument involved nearly three years of labour a1 1 failures, The great mirror for the Paris siderostat was cast at Jeamont in a special crucible with " capacity of 20 tons, Out of twelve discs cast, only two were sutisfactory.
Tntend visitors to. the Exhibiti may ask themselves how t telescope is to he employed, it being evident to the anest- capacity that the stars carnot be sighted in the daytime. The rep that photographs taken with the telescope will be show, with a magic lantern, on a screen ina large ball adjacent to the iustrument.
Phe telescope has been constructed for a company headed Franco Delonele, who was prominent ago as an Anglophobe po his defeat by Comte Boni d the last general election, M. Deloncle has entirely disappeared from public life. No doubt he will find his telescope more remunerative than patriotic surveillance of perfidious Albion, 9th March. of the Nation exten ling between the Pout des Inv; ut de Alma, Nearly all the 4 Powers are represented on the river front, the inner line being left to less impor nations; but the allo vent of sites seems to have been determined less by the sta ing of the country was buildin: Prineipulity of Monae for ins ce, has a lofty custellated str ture in of xuch comparatively t Bivain and As trin quite into t he the buildings on the civer fro ut Umy stand, proceed east to st, the first an Italy lofty, eat herr. ture of the Venetian order, with a large central dome avd elaborate windows, The Turkish pavilion next duer, also provided with ® dome, and resembling This, again, has a dome, the Capitol. Pacing portion ornaments Inuns and sari ated by ere blematical of the Golde: of 1. erty an the cur of Progress, the portico mo: tal and is to be placed. not yet arrived, but it is he will on time.') Th building is tented to he useful as well as ornamental, i Woodward, the the Ameri with his. fri his ides, his facilities for typewriting, his i post ey exchange o-water. Hem: ut his and receive the opening from New York and Chie THe acsTnt is a speci the curious n of style in vi we in the early part of the eighteenth century. Lest anyone shoul happen to be ignorant of the elvaracteristic ies of the barnes style, as displayed in the Austrian pavilion, as i is Q with a ssu: Tac lower fluor of the building is to he devoted to a beer xalo the upper to y of Austrian news wise om Aman rink cool beer the floor is hard likely to wal upstairs twelve hund-ed news pers in the G.
Tanuuage, unless he requires an excuse second thirst. ned provinces of house, pr contrast with its more elaborate Next to iti
Text read from the printed page and cleaned; old type leaves the occasional error.