Scientific American
Supplement.
No. 467

THE NEW BUILDING OF THE TECHNICAL HIGH SCHOOL OF BERLIN.

The Berlin Academy of Industry and the Academy of Building were united in 1876 to form the Technical High School. It was found that the buildings were not sufficiently large for the great number of scholars, and arrangements were made for erecting new buildings affording better accommodations. The first design was made by Lucal, who, after his death, was succeeded by Hitzig, who died in 1821, and who was succeeded, in turn, by Mr. Raschdorff.

The main building is shown in the annexed cut, taken from the Illustrirte Zeitung. It is four stories high and 754 ft. long, and the middle and side wings are about 656 ft. deep, the portions between the wings being about 164 ft. deep. In the interior five square courts are arranged, of which two are at the right and two at the left, and are separated by intermediate building. The middle court in the central portion of the building is covered by a glass roof and forms a vestibule surrounded by arcades, the halls of which lead to different rooms. In the middle portion are the rooms for the officers, and the reading rooms. The courts are erected in brick with sgraffito ornamentation; and the front, sides, and rear are erected in sandstone on a granite base. The first story, or ground floor, is of a yellowish color, and the upper story is of a clear whitish-gray. The building is richly ornamented by statues, busts, reliefs, and groups representing the different architects, artists, scientists, etc.

THE NEW TECHNICAL HIGH SCHOOL AT BERLIN.

THE NEW UNIVERSITY BUILDINGS AT STRASSBURG.

The buildings of the University of Strassburg are arranged in two groups; one in the northern and the other in the southern part of the city. All the buildings of the medical department were erected in the neighborhood of the hospital, which is located between the south wall of the city and the River Ill.

In front of the old "Fischerthor," or Fishergate, the college house, or college building proper, in which are located the offices, lecture rooms, etc., was erected. A front perspective view of this building is shown in the lower part of the annexed cut, taken from the Illustrirte Zeitung. Behind this main building, and between the Universitäts and Goethe Strasse, the buildings of the Chemical Institute, the Physical Institute, with its tower; the Botanical Institute, with the gardens and hothouses, and the Astronomical Institute, with its observatory and movable dome, are located. These buildings were designed by the architects Hermann, Eggert, Brion, and Salomon, all of Strassburg.

GENERAL VIEW OF THE STRASSBURG UNIVERSITY BUILDINGS.

THE COLLEGE HOUSE OF THE STRASSBURG UNIVERSITY.

The main building was designed by Prof. Warth, of Karlsruhe, and the style of the same is a noble Italian renaisance of the early period. Upon a base of red sandstone the basement is erected in freestone rustic masonry, upon which the first story is erected in smooth stone with conspicuous joints. The top story is constructed with arched windows separated by Ionic columns or pilasters. The central portion, which projects from the front of the building, has a grand staircase and two corner pavilions. The upper part of the central portion is constructed with fluted Corinthian columns, between which niches are provided, in which busts of the ideal representatives of the faculties are placed, viz., Homer, Paulus, Solon, Hippocrates, Aristotle, and Archimedes. Above the cornice, in the tympanum, is placed a group, of which Athene, with the torch of science, is the main figure. In the niches in the pavilions at the corners of the middle portion are the statues of Germania and Argentina, the representative of the free city of Strassburg. The pavilions at the ends of the building are ornamented by thirty-six statues of German scientists. The middle portion of the building directly beyond the grand staircase is occupied by a large open court, having a rich glass roof. The left part of the lower story is divided into lecture rooms, and the right side into rooms for the officers, etc. The collections are in the upper story, and the chapel, or main hall, is in the middle of the building.

THE WAVE THEORY OF LIGHT.1
By Sir William Thomson, F.R.S., LL.D., etc.

The subject upon which I am to speak to you this evening is happily for me not new in Philadelphia. The beautiful lectures on light which were given several years ago by President Morton, of the Stevens Institute, and the succession of lectures on the same subject so admirably illustrated by Prof. Tyndall, which many now present have heard, have fully prepared you for anything I can tell you this evening in respect to the wave theory of light.

It is indeed my humble part to bring before you some mathematical and dynamical details of this great theory. I cannot have the pleasure of illustrating them to you by anything comparable with the splendid and instructive experiments which many of you have already seen. It is satisfactory to me to know that so many of you now present are so thoroughly prepared to understand anything I can say, that those who have seen the experiments will not feel their absence at this time. At the same time I wish to make them intelligible to those who have not had the advantages to be gained by a systematic course of lectures. I must say in the first place, without further preface, as time is short and the subject is long, simply that sound and light are both due to vibrations propagated in the manner of waves; and I shall endeavor in the first place to define the manner of propagation and mode of motion that constitute those two subjects of our senses, the sense of sound and the sense of light.

Each is due to vibrations. The vibrations of light differ widely from the vibrations of sound. Something that I can tell you more easily than anything in the way of dynamics or mathematics respecting the two classes of vibrations is, that there is a great difference in the frequency of the vibrations of light when compared with the frequency of the vibrations of sound. The term "frequency,"