Globes fall into two broad categories: terrestrial and celestial. Terrestrial globes are spherical maps of the world, and celestial globes use the earth as an imaginary centre of the universe to map the stars in spherical form. A globe is the only “true” map of the world because there is no distortion in relationships of areas, directions, or distances. The actual flattening of the true earth at its poles and “fattening” around the equator are such small, real distortions that they don’t appear at the scale of globes.
Globe making developed rapidly during the European Renaissance as a result of technological developments such as printing, and the availability of Latin translations of Ptolemy’s treatise Geographica in the early 15th-century. The earlier Islamic tradition of globe-making focused mainly on the celestial globe, but Ptolemy’s work and new discoveries made by European voyagers provided the stimulus to develop the terrestrial globe as a scientific instrument. By the end of the 15th-century, globe-making had become a well established craft in Europe.
German geographer Martin Behaim made the earliest terrestrial globe that has survived. Behaim’s accomplishment was timely; he made his globe in 1492, and Christopher Columbus was almost certainly aware of it and strengthened by it in his conviction to sail West to find the Orient. Today’s globes would not be the same without the Flemish geographer Gerhard Kremer who is better known by the Latin form of his name, Gerardus Mercator. Mercator lived from 1512-1594 and was also a cartographer, mathematician, astronomer, and engraver. He is best known for having developed the type of map, now called a Mercator projection, in which all the meridians and longitudinal lines are parallel and the lines of latitude intersect these at right angles and are also parallel to each other. The Mercator projection simplified map reading; for instance, a navigator can plot a ship’s course between any two points in a straight line and follow that course without changing compass direction. Mercator also widely influenced all other aspects of mapmaking; the world atlas is also his invention. He made Louvain, Belgium, the center of the world of cartography and scientific instruments; and, there, he and Myrica Frisius constructed terrestrial and celestial globes in 1535-1537.
Earlier celestial globes were usually made of metal and were the work of silversmiths and engravers. But with the invention of the mechanical printing press in the 15th-century, it became possible to print paper gores which could be cut and pasted onto a sphere. The craft of globe-making therefore became the province of printers and publishers.
In the past, globes were generally solid and made of a variety of materials including glass, marble, wood, and metal. Hollow globes, including those made in Mercator’s day, were produced from thin metal sheets including copper.
The construction of the printed globes often began with creating a hollow sphere out of pasteboard glued together in layers similar to papier-mâché. Two hemispheres were created which would then be mounted on a wooden frame and axle and sewn together. The sphere would then be covered in plaster and turned against a former to create a smooth surface. Inevitably the weight would not be distributed evenly and the globe would be imbalanced. The process of balancing the globe involved gluing small packages of lead shot in cloth on the inside of the globe to prevent it from slumping into one position. Printed gores would then be cut from paper and pasted onto the plaster sphere.
Today, globes are almost always hollow and can be made of any material that is both strong and lightweight. Cardboard, plaster of paris, plastics, or metals can be used. We also now can more accurately balance the globes.
Above: Making a sphere out of Plaster of Paris, Bellerby & Co Globemakers.
Link : Glossary of Globe Terminology.