Brazil

Pyhsics Teaching and the s’ Gravesande Ring

Luna Abrano Bocchi

Have you ever seen the object above? What do you think it was used for?

This instrument is known as a s´ Gravesande ring and it is used to demonstrate the dilatation of metals by heat. Parallel to the wooden base, there is a metal ring connected to the main stem. The ring´s diameter allows the sphere, also made of metal, to pass through it at room temperature; however, if the sphere is hot, it expands and will be no longer able to go through the ring.

The object featured in the photo is part of a collection of objects previously used during lessons at a Brazilian school, the Colégio Marista Arquidiocesano, in the city of São Paulo. This is a Catholic institution that was established in 1858 and was originally a boarding school for boys. Since then, the school has gone through many changes and now, for instance, teaching objects which were once considered modern and up-to-date are no longer seen as such and are now on display at the school museum.

This is precisely the case of the s´ Gravesande ring.  Nowadays the device will just be seen on display in school corridors, along with several other historic scientific objects of different shapes, sizes, and purposes. The exact year when the s´ Gravesande ring was purchased for the school remains a mystery, but it is known that by 1900 a model was made available to the school’s physics department. At this time, teachers and educators believed science classes should become more practical and experimental.

Similarly, to other Brazilian institutions in the late 19th and early 20th century, the Colégio Marista endeavoured to acquire such new and innovative scientific instruments to be used for the teaching of students. In secondary schools, the s´ Gravesande ring and other tools were utilised to exemplify phenomena. Physics, as well as chemistry and natural history benefitted from a range of objects and instruments being purchased by schools to allow for a more advanced and interesting teaching practices to be explored by teachers and students. Previously, lesson content was commonly taught orally, with the aid of images and textbooks. In contrast, the use of these kind of instruments was considered pioneering as it allowed students to see the phenomenon with their very own eyes, giving scope to a higher level of understanding.

Such activities were conducted in normal teaching classrooms but there were also designated spaces for such experiments within the school building. Initially, there was a specific room used to shelter the physics cabinet which ensured the safety of the objects and equipment. Eventually, following further developments in science, new spaces were created specifically designed for scientific classes, including appropriate shelving and cabinets for the instruments, special furniture for science classrooms and sufficient room to accommodate both teachers and students.

During this time, materials were very expensive with many of them produced and sold by companies in Europe. Objects of various sizes, quite often requiring extra care and handling, had to cross the Atlantic Ocean in order to reach schools in Brazil. Lenses, microscopes, wall charts, human body anatomy models and taxidermy animals are examples of delicate products which were often chosen from catalogues and then shipped to São Paulo.

By 1933, the educational collections of Colégio Marista contained hundreds of objects including the s´ Gravesande ring. The model, as shown in the photograph, was made by Mayson Deyrolle, a French company. It may seem curious that an instrument produced in France was purchased by a Brazilian school in a period when distances between countries seemed much further apart and more inaccessible than nowadays, given the time it would take to communicate internationally. Even more curious is that, many years earlier, the device was originally created by Willem Jacob s´ Gravesande, a Dutch mathematician and philosopher. The well-known professor at the University of Leiden used different instruments in his classes for demonstration purposes, many of which he himself had designed, produced, and improved with the aid of an instrument-maker he used to work with. The ring and ball, one of his inventions, carries his name. Over time, it began to be used by other academics and teachers, eventually becoming a classic in the science classroom; since, being reproduced and sold by many companies with its picture and diagrams appearing in a great number of school textbooks.

Nowadays, three s´ Gravesande rings are found at the museum of the Colégio Marista Arquidiocesano.  By merely looking at them, one cannot imagine the history behind them – the combination of different times, places and purposes. Although they are no longer used in physics classes, they now convey a different meaning as they stand on display today, alongside other learning tools.

Word: Physics.

Number: 1858.