Volume I Part 18 (1/2)

Peter Apia.n.u.s (Bienewitz or Bennewitz) (1495-1552) was a native of Leisnig, Saxony.[345] His earliest education was received in the village of Roschlitz, but at the age of twenty-three he entered the University of Leipzig, where it appears that astronomy and mathematics chiefly claimed his interest (Fig. 71). In 1527 he received and accepted an appointment as professor of mathematics in the University of Ingolstadt, and in 1541, for his distinguished abilities, he was enn.o.bled by the Emperor Charles V. In addition to the fame acquired through his mathematical treatises he became widely known as a maker of physical and astronomical instruments, among which were celestial globes. Numerous as appear to have been these globes of his construction, no example at present is known bearing the unmistakable evidence of his workmans.h.i.+p.

Clemens, in his description of the Library of the Escorial,[346] gives us to understand that it possessed at one time one or more Peter Apia.n.u.s globes, which were probably carried to Spain by the Emperor himself.

It seems probable that a diligent search through public and private libraries and museums in that country would lead to the discovery of some of his globes or mathematical instruments.

[Ill.u.s.tration: Fig. 71. Portrait of Peter Apia.n.u.s.]

Kepler tells us of an Apia.n.u.s globe which he saw on a journey from Wurtemberg to Gratz, noting that it was so constructed that the stars could be removed at pleasure from the sphere.[347] Of this particular globe nothing seems now to be known. It is thought hardly probable that the one referred to by Kepler is that fine celestial Apia.n.u.s globe (Fig.

72) belonging to the K. B. Hof- u. Staats Bibliothek of Munich. There seems to be scarcely a doubt that this, as its companion, a terrestrial globe, is the work of the son Philip. Repeated inquiry has not resulted in obtaining definite answer as to the dimensions of these globes nor a description of such detailed features as would here prove of interest.

The photographic reproductions show them to be of remarkably artistic workmans.h.i.+p. Each is furnished with a heavy meridian circle, and with a similarly designed horizon circle supported by a semicircle which rests upon an elaborately constructed base.[348] The history of these globes seems not to be known, as stated above. We have an inventory of the Herzoglich-Bayrische collection of mathematical and astronomical instruments, prepared by the Jesuit, Fickler, which contains, page 147, the following entry relative to the globes to be found therein: ”Folget die Tafl. Nr. 34. Daraus stehen drey grosser hulzinen Globi Coelestes, davon d. ain in einem messingen gestell, mit ainem messingem zodiaco, der dritt von mettall. 1777. Sechs grosser Globi terrestres von Holz.

mit mettallinen zodiacis 1778. Zwei claine Globi der ain Coelestis der ander Terrestris, auf gedraxelten holzen fuesslen.”[349] ”Next in order is table No. 34. On this there stand three large celestial globes of wood, one of which has a base of bra.s.s, with a bra.s.s horizon circle, the third of metal, 1777. There are six large terrestrial globes of wood, with metal horizon circles, 1778. Two small globes, one celestial, the other terrestrial, resting on turned wooden feet.” It will be noted, however, that there is no mention therein of Apia.n.u.s globes. Kobalt tells us that Apia.n.u.s ”vertigte allerley mathematische instrumente, als Cosmolabium, Globos duos Caeli et Terrae maximos, und Planisphaerium,”

”constructed many kinds of mathematical instruments such as astrolabes, two large globes celestial and terrestrial and planispheres.” This same author gives us the information that ”in der k. b. Central-Bibliothek befinden sich zwei grosse, von Apian ververtigte und von Johann Mielichs gemalte Globi Coelestes et Terrestres, worauf folgende Inschrift zo lesen ist, 'Ill.u.s.trss Seren. Principi ac Domino D. Alberto Com. Pal.

Rheni. Sub. Inf. que Bar. Duci Domino suo Clementissimo Glob.u.m hunc geographic.u.m cels. ejus jussu juxta veterum ac recentium Historiographorum Observationes Traditionesque Descr. et Ded. Philippus Apia.n.u.s M. D. Anno Salutis 1576.'” ”In the K. B. Central Library there are two large globes celestial and terrestrial constructed by Apia.n.u.s and painted by Johan Muelichs, on which is the following inscription: 'To the Most Ill.u.s.trious, Most Serene Prince and Lord D. Albert Count of the Rhenish Palatinate, etc. His Most Clement Lord this celestial globe by his command, fas.h.i.+oned according to the observations and traditions of both ancient and modern historiographers dedicates Philip Apia.n.u.s in the year of Salvation 1576.'”[350] It seems, therefore, probable, from the above citation, that it was the son Philip who constructed these Munich globes. It was in the year 1552 that he followed his father as professor of mathematics in the University of Ingolstadt and like his father soon won distinction for himself as cartographer, producing his famous Bayrische Landtafeln as his first work of note. It seems further probable that shortly after this work he became interested in globe construction, in which line of activity he made for himself a place of first rank.

[Ill.u.s.tration: Fig. 72. Globes of Philip Apia.n.u.s, 1576.]

The celestial globe referred to above has represented on its surface the several Ptolemaic constellations, exquisitely colored, and the stars have been given names in Greek, Latin, and Arabic. The terrestrial globe map is considerably injured, especially in the polar regions, but the continental and other outlines are all clearly traceable. Three large compa.s.s roses, of ornamental pattern, are placed along the Line of Demarcation. The coast outline of Europe is, in the main, well done, as is that of Africa and the New World. The Nile and the Niger rivers no longer find their source in the same common lake. The representations of the far eastern regions indicate that Apia.n.u.s had a fairly good knowledge of the records of the Holland explorers.

A fine example of the metal worker's art of this period may be found in a silvered bronze celestial globe (Fig. 73) belonging to the Morgan collection recently placed in the Metropolitan Museum of New York. On the meridian circle we find the maker and date legend reading ”Gerhard Emmoser, sac. caes. meis horologiarius, F. Viennae 1579.” The sphere, which can be opened on the line of the ecliptic, has a diameter of about 13 cm. Within has been placed a delicately constructed mechanism by means of which the sphere is made to rotate once in twenty-four hours on its equatorial axis, the key winding stem for this machinery projecting at the north pole through an engraved hour plate with pointer. With its meridian and its horizon circle it is adjusted to make one revolution in three hundred and sixty-five days. A stationary ring, about 2 cm. in width, which closely surrounds the horizon circle and in its same plane, fits the instrument as a calendar. This ring has engraved on its surface crossing lines, one for each day of the year, to each month there being a.s.signed its proper number of days or lines, as, for example, ”October habet 31 dies,” ”November habet 30 dies.” As the sphere with its circles revolves, a pointer attached to the horizon circle indicates on the calendar ring each day of each month in succession. The surface of the sphere is exquisitely engraved with representations of the several constellations, the name of each being given in Latin. The instrument is made to rest upon the back of a winged horse in silvered bronze, this in turn standing upon an artistic circle base. It is well preserved and is a choice example of such instruments, which in this period were in particular favor.

[Ill.u.s.tration: Fig. 73. Silver-Gilt Globe of Gerhard Emmoser, 1573.]

Carlus Platus, a maker of metal globes in the last quarter of the sixteenth century, is known to us through two fine extant examples of his work.[351] The first of these, inscribed ”Romae a. 1578 Car. Pl.,”

may be found in the Museo di Strumenti Antichi of Florence, having been added to this collection by its former distinguished director, F.

Meucci. The horizon diameter of this armillary sphere is about 21 cm. It has been described as one beautifully constructed of bra.s.s and mounted on a carved wooden base. The circle representing the course of the sun and that made to represent the course of the moon are made to revolve on the axis of the ecliptic, and a small ball, of recent construction, representing the earth, is placed in the common center of the armillae, and is made to revolve on the axis of the equator. A dial attached to the axis of the earth below the meridian circle marks the hours, which are engraved on the Arctic polar circle. A few points marked on the colures indicate the position of the princ.i.p.al stars. All of the circles have been carefully graduated. On that one representing the zodiac have been engraved the names of the months and the pictures of the several zodiacal figures, while on the horizon circle are the names of the princ.i.p.al winds in Greek, Latin, and Italian.

A second globe of Platus, signed ”Carolus Platus Romae Anno 1598,” may be found in the Biblioteca Barbarini of Rome. It is composed of two hollow bra.s.s hemispheres, making a ball 14 cm. in diameter, which is surrounded by a bra.s.s meridian and a bra.s.s horizon circle, the whole resting on a tripod base. It is a fine example of an early metal engraved globe, the representation of the figures of the constellations in particular being done in a very superior manner. On the surface of the sphere the equator, the ecliptic, the equinoctial, and the solst.i.tial colures are represented. The history of the globe seems not to be known, but it is probable that it came to the Barbarini Palace in the time of Pope Urban VIII, who, before filling his pontifical office, was known as Maffeo Barbarini.

Of the celestial globes constructed by George Roll and Joannes Reinhold three examples are known.[352] One of these may be found in the collection of the Mathematical Salon of Dresden (Fig. 74) one in the Osservatorio di Capodimonte of Naples and one in the K. K. Hofbibliothek in Vienna. The Roll and Reinhold globe of the Dresden collection, bearing the inscription ”Georg Roll et Joannes Reinhold elaborabant Augustae 1586,” is an exceedingly interesting instrument, unique in the manner of its construction and remarkably well preserved. It is of bra.s.s, having a diameter of 36 cm., and is furnished with numerous movable circles, a large meridian circle surmounted with an armillary sphere, and a bra.s.s horizon circle on which are marked the old and the new calendars, the names of the twelve months and of the important holy days. The globe base, very artistically wrought, rests upon four griffin's feet, between which a small terrestrial globe 10 cm. in diameter has been placed, this having been furnished with its own independent support. The large celestial sphere is furnished with a clocklike mechanism by means of which it is made to revolve in representation of the diurnal motion of the heavens. According to existing records it was purchased in the year 1593 by order of the Elector Christian II, and by him was presented to the Academy of Arts of Dresden. Zeiller tells us that this and the Heyden globe were those ”with which the Prince Elector Augustus was accustomed to amuse himself.”

[Ill.u.s.tration: Fig. 74. Globe of George Roll and Johannes Reinhold, 1586.]

It has not been possible to obtain a description of the Vienna globe. It appears that it was constructed in the year 1588, and that, like the Dresden example, the celestial sphere is made to revolve by means of clockwork.

The Roll and Reinhold globe belonging to the Osservatorio di Capodimonte, according to Fiorini, is one especially worthy of mention.[353] This is described as a hollow ball having a diameter of about 21 cm. The sphere itself is made of copper, the remaining parts of gilded bra.s.s. The horizon circle is composed of several overlapping bra.s.s plates. A clockwork mechanism is supplied, by means of which the sphere and certain circles may be made to revolve. The surface of the copper sphere is artistically engraved, having numerous circles representing the ecliptic system with its parallels and meridians, and the equatorial system including its five zones. The Ptolemaic constellations are represented, the figure of each being engraved in outline with the name in Latin. The several stars are not named but near each is an engraved number to indicate its magnitude, these numbers ranging from 1 to 6. Nebulae are distinguished by small circles, and the Milky Way by numerous dots. The meridian circle, in which the sphere revolves, has the usual graduation from 0 to 90, but has in addition a climatic graduation designed ”Climata ex Ptolomeo,” and a division into zones called ”Torrida Zona,” ”Zona habitabilis temperata,” and ”Frigida zona.” On the convex surface of the horizon circle we find engraved the names of the four cardinal points, and on the upper surface of this circle are engraved the Julian and the Gregorian calendars, the names of the saints, the dates on which the sun enters the various signs of the zodiac, and the ancient names of the princ.i.p.al winds. The globe mountings, all of bra.s.s, are artistic and well preserved. Like the Dresden example it rests upon a four-branched support, the extremities of each branch representing the claws of the griffin. Including the base, the instrument is 43 cm. in height. It seems not to be known when or how this globe, constructed in Augsburg, found its way to the Naples Museum, where it is treasured as one of the choicest of ancient astronomical instruments.

Tycho Brahe, the great Danish astronomer (Fig. 75), was a native of Knudtstrup near Helsingborg, born in the year 1546.[354] The care of his early education was a.s.sumed by an uncle, George Brahe, who in the year 1559 sent him to the Academy of Copenhagen with the intention of fitting him for the legal profession. Three years later we find him registered at the University of Leipzig, then famous for its department of jurisprudence. Like many another of the world's great men for whom, in the days of his youth, interested relatives or friends have chosen a life career only to find in later life the choice not well made, Tycho's bent was not for the legal profession but for science, that is, for mathematics and astronomy. While yet a student in Copenhagen an eclipse of the sun which occurred August 21, 1560, interested him greatly, and here we seem to find the beginning of that great future which was to be his. Forbidden by his schoolmaster to give his time to a study of the stars, in the quiet of the night he would secretly betake himself into the open, there to watch with unaided eye the movements of the heavenly bodies, or to follow these movements as best he could with the a.s.sistance of a simple astronomical circle and a small celestial globe which he had been able to purchase. It probably was in his Leipzig days that he became intimate with Bartholomaus Scultetus (Schultz), lecturer on mathematical subjects, and by him was encouraged to pursue further his astronomical studies. Among the first practical results of his activities in this field we have his correction table for readings with the Jacob staff. The death of his uncle in the year 1565 occasioned his return to his native country, but Germany offering him special opportunities for continued study in his favorite field, we soon find him in Wittenberg, later in Rostock, where in a quarrel with a peasant he lost part of his nose and thereafter to the end of his days wore a silver subst.i.tute. In 1567 we find him in Lauingen engaged in the study of astronomy with the distinguished Cyprian Leowitz, in 1568 in Basel with Peter Ramus, and for two years thereafter in Augsburg with the brothers Johan and Paul Hainzel, with whom he constructed a large quadrant having a radius of seventeen and one half feet. While in Augsburg it appears that he began the construction of a celestial globe four feet in diameter, but there is some uncertainty as to his completion of this work. A short but unhappy sojourn in his native town followed his years of congenial study in Germany, and we soon learn of his visit to the observatory of Landgraf Wilhelm of Ca.s.sel, an event of great significance for him. His travels carried him to other cities of Germany, including the city of Regensburg, where he witnessed the coronation of the Emperor Rudolf II. Landgraf Wilhelm, a Maecenas of wide repute in his day, had been greatly impressed with the abilities of Tycho, and he urged upon the Danish King Frederick that he should make suitable provision for the further astronomical studies of his distinguished subject, which suggestion the King generously met. In the year 1575 the doc.u.ments were signed and sealed granting to Tycho full possession for life of the little Island of Hveen, lying between Seeland and Schonen; in addition he was furnished with all the means necessary for the erection of an observatory and the adequate equipment of the same (Fig. 76). The Uranienburg, as his observatory was called,[355]

became a great center for astronomical studies, and students came to him from various European lands, among these being Arnold van Langren, Willem Jansz. Blaeu, and Longomonta.n.u.s (Christian Severin of Longberg).

The death of his patron, King Frederick II, in the year 1588 brought misfortune to Tycho, in so far as his life and studies on the Island of Hveen were concerned, since the succeeding ruler, Christian IV, was but little interested in the further promotion of astronomical science.

Enduring court intrigue for nine years, he determined, in the year 1597, to leave the scenes of his remarkable successes, and after a brief sojourn with Count Henry of Ranzau near Hamburg, he accepted an invitation from the Emperor Rudolf II to become imperial astronomer and counselor at Prague. Thither he went with his family in the year 1599, at the same time taking with him those astronomical instruments which had served him in his studies in the northern island home. While preparations were under way for the erection of a new observatory for him he died in the year 1601. From Tycho's heirs the Emperor Rudolf purchased his instruments and ma.n.u.scripts, the latter pa.s.sing into the hands of Kepler, his successor at the Imperial Court, but as to the fate of his instruments little seems to be known. Kastner tells us that in 1619, during an uprising in the city of Prague, some of these were destroyed while others were carried away, and at present only an iron quadrant, once in his observatory, remains in that city.

[Ill.u.s.tration: Fig. 75. Portrait of Tycho Brahe.]

[Ill.u.s.tration: Fig. 76. Interior of Tycho Brahe's Observatory at Uranienburg.]

His large bra.s.s celestial globe, six feet in diameter, was carried back to Copenhagen in the year 1623 by King Christian's son, Ulrich, and there it was carefully kept until the year 1728, when with the castle in which it had been placed it was destroyed by fire.

Recalling the far-reaching influence of Tycho Brahe on astronomical studies and on celestial globe making, it cannot be without interest to quote here his own reference to his great globe, wherein he describes its construction.

”This globe,” he says,[356] ”which is a very large one, we have made with great care, but with none the less than we have employed in all of our others. The interior is of wood with many intersecting circles and special supports, strengthened here and there from the center, and being then fas.h.i.+oned into a spherical shape. As for its parts of wood, these were made at Augsburg in the year 1570 before I returned to my native land, as I found there a capable workman, having sought for a long time elsewhere in vain for such an one. There, on account of its size, which made it difficult to move, it had remained for five years, when I returned to Augsburg; this was in the year 1575 as I came out of Italy on my way to Ratisbon to be present at the coronation of the August Emperor Rudolf II, when I found the globe had been finished some time previously. But its shape (sphericity) did not altogether satisfy me, moreover certain cracks could be seen. In the following year, and not without much difficulty I had it carried to Denmark. There the cracks were filled in and the sphericity made more nearly perfect by laying over the surface about one hundred skins. There followed a testing for a period of two years to ascertain whether the cracks would reappear after two summers and two winters. When, after this test, I saw that it retained its sphericity, I covered it over with thin bra.s.s plates of uniform thickness without mishap, and this I did with such care and skill that you would be led to say the globe was made of solid bra.s.s, the joinings of the plates being scarcely visible. I next fas.h.i.+oned it into a perfect sphere and marked thereon the zodiac, and the equator with its poles, also the degrees each of sixty minutes by engraved lines as we do in such work. I then left it for the s.p.a.ce of one year, as there was some doubt after putting on the bra.s.s plates as to whether the globe would retain its sphericity in winter and in summer. When it had been sufficiently tested not only did I indicate the circles of which I have spoken but also all the stars of the eighth sphere I represented in their proper places, as many stars as were to be seen in the heavens, and I increased their number more and more in succeeding years up to 1600. Thus I with purpose added all the stars visible to the naked eye, in their proper places adapted to the year 1600 which was near at hand.