Some mathematical objects also exhibited here like this Gunter’s square made in 1567. Gunter also invented his scale for computing adapting the new logarithms invented by Napier in 1614. Hence, it’s time to start our visit to all the Napier’s rods and slide rules of the exhibition. Let’s have a look to a couple of them, like these English Napier’s rods from 1720…
or this other ivory set made from the 17th century:
From Gunter scales the slide rules were invented and this spiral logarithmic scale by John Holland (1650) is a very good example of the great inventions of the men from the Renaissance:
After the slide rules and before the computers, ihis fragment of the ‘Difference Engine No. 1’ by Charles Babbage (1832-3) assembled by his son Henry Babbage (c.1880) must also be exhibited:
Finally, a very curious mathematical object: this magic cube made by A. H. Frost in 1877:
Each row, each column and each diagonal have the same sum!
I must finished this wonderful walk for the calculating machines going downstairs to the groundfloor again and showing some instruments more. Number 41 is a calculating machine from c.1955 made by Bell Punch Company Limited and number 42 is the ‘Eckel dial rule’ from the same year. The calculator number 51 is from 1955-1965.
Among the instruments which made our life more confortable there is also space for the sundials, clocks and quadrants. For example, look at this Gunter’s quadrant from the beginning of the 19th century:
One example of sundial is this inclining sundiel from 1800:
Finally, we notice this universal ring dial from the mid-eighteenth century. Sundials were still needed to set the clocks and watches that had superceded them as timekeepers:
John Napier invented published his Mirifici Logarithmorum Canonis Descriptio in 1614 and the invention of the logarithms was the beginning of a new method of computing. Henry Briggs met Napier in Edimburg in the summer of 1615 and 1616 and these two men together decided to improve the invention creating the decimal logarithms which were published by Briggs some years later. In 1620 Edmund Gunter published his Canon Triangulorum where he described one of the first attempts to create a slide rule:
After the Gunter’s scale was invented, some other descriptions of the rule appeared like the one made by Wingate in paris in 1624. Gunter’s scale was very popular because all the trigonometrical resolutions of the triangles were reduced to additions and substractions on the rule:
The slide rule was invented by William Oughtred who designed both a circular and a straight form of slide rule in about 1621 but did not publish his work until much later. Richard Delamain, one of his former pupils, published a description of a circular slide rule in 1630, and claimed priority of invention although he copied Oughtred’s ideas. In 1660’s Thomas Browne invented the spiral slide rule consisting in fixed scales and moveable index arms similar to Oughtred’s circles of proportion: