1844. 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



3S1 



tnents to observation of the stars. Thus, in 1732, no place in the 

 large building could be found adapted to receive a mural quadrant of 

 six feet radius ; an enclosure covered with vaults entirely closed and 

 having vifalls of extreme thickness and considerable height would no- 

 where have allowed a continuous meridian opening, through which it 

 would have been possible to discover all the stars from the horizon to 

 the zenith at the time of their culmination. The Academy of Sciences 

 was obliged, therefore, to set up an external chamber contiguous to 

 the eastern tower. In 1742 the same difficulty occurred with regard 

 to a moveable quadrant, and a second chamber was put up alongside of 

 the other. A few years after, in 1760, a little turret with a turning 

 roof was erected, to the south of the two former appendations, in 

 order to facilitate observations of corresponding altitudes for the dr- 

 termination of the exact lime of phenomena. These three little 

 rooms, constructed with extreme parsimony and withoit durability, 

 for many years formed the real observatory at Paris. The majestic 

 edifice of Perrault towered over these hovels, but it only constituted 

 to make use of an expression of the time, a show observatory. 



This great observatory, moreover, like most of the other monuments 

 of the capital, had suffered from the carelessness and inattention 

 which characterised the latter years of Lewis XV. In 1770 it was 

 falling into ruins. Care was obliged to be taken in entering the 

 rooms, particularly after a thaw, and the walls and arches were falling 

 to pieces, ruined by the rain water. The incessant applications of 

 Cassini the Fourth, backed by the reports of the Academy of Sciences, 

 were at last listened to, in 1775, by M. D'Angivillers. This en- 

 lightened minister determined that the restoration of the edifice 

 should be forthwith attended to. For more than a century the astro- 

 nomers in their various pursuits had had to suffer from the bad ar- 

 rangements of the old observatory. This explains why Cassini pro- 

 posed to pull down all the building above the meridian room story. 

 M. D'Angivillers, however, strongly objected to this. The work of 

 Perrault, said the minister, from its imposing mass and severe style, 

 must be ranked as one of the chief ornaments of the capital. It was 

 not possible to propose seriously to Lewis XVI. to destroy a monu- 

 ment erected by his forefather, a monument which was not yet a hun- 

 dred years old, and where besides the great king had used to go and 

 observe in person. Further, the Intcndant General of Crown Build- 

 ings might have rejected any plan of demolition on other grounds — on 

 those of brilliant scientific remembrances. It was in this building, 

 then condemned to the hammer, that Picard, rejecting the ancient 

 pinnulffi, applied telescopes provided with wires to graduated instru- 

 ments, and thus laid the foundation for the exactness of modern obser- 

 vations. It was there, also, that the life of astronomers was doubled, 

 if we are allowed the expression, by showing that the stars could be 

 as well observed in the brightest sunshine as in the depths of night. 

 It was in the building threatened with destruction that Picard and 

 Auzout, bringing into use the filar micrometer of their invention, for 

 the first time calculated with precision the angular diameter of the 

 stars, and thvis surmounted difficulties against which the genius of 

 Archimedes had failed. The rooms of which the demolition was pro- 

 posed had been witness of the experiments and minute preparations 

 which were requisite before attempting, with any chance of success, 

 the celebrated measurements, executed in France, Peru, and Lapland, 

 for the purpose of determining the size and figure of the earth. 

 Richer observed there the rate of his pendulum before starling for 

 Cayenne; he verified it there after his return, and ascertained by 

 means of these comparisons a capital phenomenon, that the weight of 

 bodies is affected as they approach thr equator. J. D. Cassini, shel- 

 tered by the same roofs, laid down the remarkable laws of the libration 

 of the moon, discovered four of the satellites of Saturn, the movements 

 of rotation of these new stars and those of the satellites of Jupiter, the 

 flattening of that immense planet, and the zodiacal light. It was, in 

 fine, in those halls that the first serious suspicion arose touching the 

 successive propagation of light, and it was by means of observations 

 of the eclipses of the sateUites of Jupiter, made from the windows of 

 the Paris Observatory, that Roiimer, an astronomer of the Academy, 

 gave the first approximate data of the velocity of a luminous ray, a 

 result which, by being carefully perfected after a century and a half of 

 assiduous researches, has been definitively fixed at 200,000 miles 

 per second. In any country, feeling an enlightened love for science, 

 such remembrances would have been amply sufficient to save the most 

 defective Observatory from destruction. 



The promise of restoration obtained from Messrs. De Breteuil and 

 D'Angivillers began to take effect in 1777, on the small closets on the 

 east tower. These first works, very restricted in plan, were carried 

 out in a still more stinted manner. On the other hand the restoration 

 of Perrault's edifice, planned with grandeur by the two architects 

 Brebion and Renard, was effected from 1786 to 17'J3, so as to defy cen- 

 turies. From 1793 to 1830 the buildings of the Observatory received 



no improvement worthy of note, but the wretched buildings which 

 masked it on all sides were demolished. In the same period were 

 executed the magnificent avenue which leads from the north facade to 

 the Luxembourg Palace ; the mound, forming on the south side of the 

 building, the planted terrace, well ada|ited for magnetic and meteoro- 

 logic observations; and the gates, railings, and retaining walls which 

 now isolate and enclose the Observatory and its appendages. 



In 1832 works more directly useful to astronomy followed up these 

 measures. In the course of 1S31 the Chiiniber of Deputies, made 

 acquainted with the real state of affairs, determined that our national 

 observatory sliould be on a par with the most celebrated observatories 

 in Europe. The Chamber voted spontaneously, and in one sum, a 

 grant double that asked by the minister. This grant allowed not 

 merely the simple repairs to be carried out according to the original 

 moderate request, but the complete rebuilding of the observing rooms 

 on the east tower. A little while after the Chamber voted a large, 

 convenient, and richly decorated theatre, which has been ably joined 

 on to the other buildings by its skilful architect, and to which the love 

 of astronomy draws a large audience. The rotunda with the moveable 

 roof dates from the same time, and is constructed on the upper ter- 

 race ; in it is now raised a fine parallactic instrument. We are stating 

 the opinions of the most celebrated astronomers in Europe, when we 

 assert that the new rooms for meridian observations unite convenience 

 and durability to elegance, and that they leave nothing to be desired 

 in the present day. 



It was not only the state of disrepair of the fine buildings of Per- 

 rault, and the restricted size of the temporary erections added to the 

 old works, which, in the Observatory of Paris, grieved every French- 

 man animated with patriotic feeling; but everywhere, down to a late 

 date, the eye was struck with instruments almost exclusively foreign. 

 If we looked at the telescopes they bore the names of Campani, 

 Borelli, Hartzcecher, Huygens, DoUond and Short. The mural circles, 

 the meridian glasses, and the great repeating circles, were the work 

 of Sisson, Bird, Ramsden or Reichenbach. The astronomical clocks 

 alone procei'ded from the shops of our countrymen. Now, all the 

 large instruments of the Paris Observatory are French, and without 

 having sacrificed exactness to national self-love (for such a sacrifice 

 would have been a great piece of dupery), we only see on the faces of 

 the eastaspect walls, or on the columns of the high or low rooms, 

 magnificent divided circles, meridian and equatorial instruments of 

 Forlin and Grambey, and every one can observe that the large achio- 

 matic telescopes, sheltered under the vaults of the old building, have 

 been wrought by the skilful hands of Lerebours and Cauchoix. What 

 has been the real origin of this radical transformation, where our 

 former inferiority appeared so well established, so sanctioned, that it 

 seemed as if it must last for ever ? The answer is very easy. We 

 said to the French workmen — Do nut seriously care for the universal 

 opinion as to an asserted innate superiority which the workmen of 

 England and Germany have over you ; go boldly to work ! These 

 words were listened to, and their success has surpassed all expecta- 

 tions. In our country, io dare is almost always synonimous with io 

 succeed. 



Of late years all the governments in Europe seemed to have agreed 

 to improve the old observatories and form new ones. In England, 

 Greenwich, already so justly celebrated, has received a great increase 

 of plant and staff. Now the observatories of Edinburgh, Cambridge, 

 Oxford, Dublin, and Armagh, may almost rival that which Flanisteed, 

 Halley, Bradley, Maskelyne, and Pond have made illustrious, and 

 which is fortunately still in very good hands. Analogous establish- 

 ments, on a vast scale, have been erected at the Cape of Good Hope, 

 Sydney and Madras. We may perh.ips be allowed, without infring- 

 ing truth, to class among the great English observatories that founded 

 by the Rajah of Travancore. ' 



The Neapolitan government did not think it had done its duty 

 towards science even after having constructed the great observatory 

 at Palermo, to which Piazzi so gloriously attached his name in the 

 beginning of this century. A fine astronomic.d observatory has within 

 the last few years been constructed at Capo di Monte, near Naples. 

 A meteorological and physical observatory is now being erected on 

 the side of Vesuvius. The observatories of Florence, Milan, Padua, 

 Turin, and Vienna would be open to criticism, perhaps, if we looked 

 at the buildings only ; but, on the other hand, the knowledge of the 

 directors, the number and beauty of the instruments, would suggest 

 unlimited praise. Every one knows the successful exertions which 

 the Belgian government has made to provide the city of Brussels 

 with an observatory worthy of our day. Every one knows too that 



1 M. Arago has not alludetl to the other uumerous and excellent observatories munifi- 

 cently maintained by private individuals, the Karl of Rosse, Lord Wriothesley, Sir John 

 Herschel, Mr. Bishop, Treasurer of the Royal Astronomical Society, Sir Thomas Bris- 

 bane, &c. &c.— Translator, 



