Each of these globes is well preserved, the colors originally applied remaining particularly bright in the southern hemispheres, these being better protected from light and from injuries incident to the more exposed upper surfaces.
In the third pair of Valk globes belonging to The Hispanic Society (Fig. [121a]) the diameter of each is about 23 cm. In geographical details, in legends, etc., each of these agrees with the preceding second pair. It is, however, to be noted that the date on the terrestrial globe has the figure 50 appearing in the date 1750 skilfully inserted after the removal of the original, and that the loxodromic lines are on this more numerous; indeed, it is one of the most interesting globes examined for the representation of these lines, which become curiously, but necessarily, somewhat intricate in their crossings as they approach the poles. Of the three pairs of these globes referred to above, this third pair seems to be the best preserved; the only injury to be especially noted is that appearing on the celestial, this being a crack in the surface extending from pole to pole. The original colors in each are particularly well preserved.
In addition to the examples of Valk globes referred to above as belonging to the University of Ghent and to The Hispanic Society of America, a pair may be found in the Königliches Museum of Cassel, said by Gerland to be dated 1715, and to have each a diameter of 45 cm., also a terrestrial globe in the same museum said to be dated, though doubtless erroneously, 1700, and to have a diameter of 23 cm., also a celestial globe of the same date having a diameter of 30 cm. In the Mathematische Salon of Dresden is a celestial globe having a diameter of 30 cm., and a pair in the Museo di Fisica of Bologna, the diameter of each being about 46 cm. The date has not been ascertained. In the Germanisches Nationalmuseum of Nürnberg may be found a well-preserved pair of the Valk globes said to be dated 1700 and to have each a diameter of 31 cm.
Fig. 121a. Celestial Globe of Gerhard and Leonhard Valk, 1750 (?).
John Senex, a noted English cartographer and engraver (d. 1749),[135] appears to have given some attention to the construction of globes, which were sold at his establishment in Salisbury Court, London. In the year 1714 we find his name associated with that of John Maxwell in the issue of ‘The English Atlas,’ and in 1721 he appears as the editor of ‘A New General Atlas.’ It was in the year 1720 that he made a representation to the House of Commons on the subject of “A New Globular Projection,” with the thought of eliciting encouragement for the employment of better methods in map construction. He became a Fellow of the Royal Society in 1728, and in 1738 read before that society a noted paper on his “Contrivance to make the Poles of the Diurnal Motion in a Celestial Globe pass round the Poles of the Ecliptic.” This globe was to be “so adjusted as to exhibit not only the risings and the settings of the stars in all ages and in all latitudes, but the other phenomena likewise, that depend upon the motion of the diurnal axis round the annual axis.” From what is stated in this paper one is led to associate his idea with that of Cassini, to which attention was directed above. If, however, such a globe was constructed as that referred to in this scientific address it is not now known. Five of his globes have been located, two of them undated, and three of them dated 1793, which, if the correct date of issue, it will be noted, is more than fifty years after his death. A pair of his globes may be found in the Bibliothèque Nationale of Paris undated. These are reported as having a diameter of about 40 cm. They are furnished with brass meridian circles, with horizon circles of wood, and each with a wooden base. The dedication reads: “Philosopho ac Geometrae summo Do Isaaco Newton, equiti, Regalis Societatis Londini, ad scientias promovendas institutae, Praesidi dignissimo, ejusdemque consilio et sodalibus hos Globos qua par est humilitate D.D. C. Johannes Senex. London.” “To the great philosopher and geometrician Sir Isaac Newton, Knight, most worthy President of the Royal Society of London, for the promotion of knowledge, and to the Committee and Members of the same Society these globes with befitting humility are dedicated by C. John Senex. London.” Further descriptive details of these globes it has not been possible to obtain.
The Biblioteca Real of Madrid possesses a terrestrial globe by Senex (Fig. [122]), which bears the title legend, “A new and most correct Globe of the Earth laid down from the latest observations from the most judicious astronomers, navigators, & travelers, by John Senex, F. R. S. Now made and sold by Dudley Adams (only)[136] with all the latest discoveries together with many new improvements etc. 1793.” This globe has a diameter of about 40 cm., is furnished with a broad band which serves as a horizon circle, a meridian circle of brass within which it is made to revolve, and a tripod base. Its three fluted support columns are strengthened in their position by three curved iron braces which carry at their juncture a short carved post, through a slot in which the brass meridian is movable. While the surface of the sphere is somewhat injured, being crossed by numerous cracks, the engraved map is fairly legible in all of its parts.
