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Title: George Atwood - Atwood’s Machine from A treatise on the Rectilinear Motion and Rotation of Bodies (Cambridge, 1784)
Format: photograph: negative
Date: 1784
Description: As mathematics tutor at Cambridge University in the 1770s and 80s, George Atwood was responsible for introducing students to Newtonianism. To help with this task -- and to quell lingering debates about inertia and the living force of matter -- Atwood fashioned a machine that soon became known eponymously. The machine employed an ingenious system of weights, pulleys and a pendulum clock which demonstrated Newton’s laws of motion.

Title: Custom House, from the River Thames
Format: photograph: negative
Date: 1808
Description: Ackermann, R., The Microcosm of London, Vol. I, London 1808 Plate no. 29a

Title: Royal Exchange
Format: photograph: negative
Date: 1809
Description: Ackermann, R., The Microcosm of London, Vol. III, London 1809-1810 Plate no. 67

Title: British Institution, Pall Mall
Format: photograph: negative
Date: 1808
Description: Ackermann, R., The Microcosm of London, Vol. I, London 1808 Plate no. 13

Title: Hospital, Middlesex
Format: photograph: negative
Date: 1808
Description: Ackermann, R., The Microcosm of London, Vol. II, London 1809 Plate no. 44

Title: A View of London from the Thames, taken opposite the Adelphi
Format: photograph: negative
Date: 1809
Description: Ackermann, R., The Microcosm of London, Vol. III, London 1809-1810 Plate no. 89

Title: Westminster Hall
Format: photograph: negative
Date: 1809
Description: Ackermann, R., The Microcosm of London, Vol. III, London 1809-1810 Plate no. 94

Title: St. Margarets. Westminster
Format: photograph: negative
Date: 1809
Description: Ackermann, R., The Microcosm of London, Vol. III, London 1809-1810 Plate no. 78

Title: William Whiston - fig.9 for A New Theory of the Earth (London, 5th edn., 1737)
Format: photograph: negative
Date: 1737
Description: Whiston’s representation of the solar system, including a prominent comet. Newton and Edmond Halley had worked hard to demonstrate that comets were predictable, periodic bodies which therefore could not be used to prognosticate divine interventions in the natural order. Yet they also suggested that comets deposited aethers to revitalize a spiritually depleted Earth. Whiston liked this mixture of close geometrical analysis with divine mechanism, and extended the discussion. He argued that comets had been responsible for key moments in the Earth’s natural and biblical history - for instance, it was a great comet that had caused the Deluge. He even equated comets with Hell: as they moved in their highly eccentric orbits, they alternated between the “Darkness of Torment” and the “ungodly Smoak of Fire.” For Whiston, comets thus became “the place of Punishment for wicked Men after the general Resurrection.”

Title: New Stock Exchange
Format: photograph: negative
Date: 1809
Description: Ackermann, R., The Microcosm of London, Vol. III, London 1809-1810 Plate no. 75

Title: Guild Hall
Format: photograph: negative
Date: 1808
Description: Ackermann, R., The Microcosm of London, Vol. II, London 1809 Plate no. 40

Title: Galileo, illustration from Discorsi e Dimostrazioni Matematiche (Discourses and Mathematical Demonstrations concerning the Two New Sciences of Mechanics and Local Motions), Leiden, 1638
Format: photograph: negative
Date: 1638
Description: The illustration is from the second day of Galileo’s Discourses, and shows that the resistance of a solid body to breaking is dependent upon its length and thickness.

Title: Heralds College, The Hall
Format: photograph: negative
Date: 1808
Description: Ackermann, R., The Microcosm of London, Vol. II, London 1809 Plate no. 43

Title: Vauxhall Garden
Format: photograph: negative
Date: 1809
Description: Ackermann, R., The Microcosm of London, Vol. III, London 1809-1810 Plate no. 88

Title: The Hall, Blue Coat School
Format: photograph: negative
Date: 1808
Description: Ackermann, R., The Microcosm of London, Vol. I, London 1808 Plate no. 10

Title: Freemasons Hall, Great Queen Street
Format: photograph: negative
Date: 1808
Description: Ackermann, R., The Microcosm of London, Vol. II, London 1809 Plate no. 38

Title: Watch House
Format: photograph: negative
Date: 1809
Description: Ackermann, R., The Microcosm of London, Vol. III, London 1809-1810 Plate no. 91

Title: Cassini’s heliometer
Format: photograph: print
Date: 1695
Description: The church of San Petronio in Bologna was the site of a solar observatory as early as 1576 when Egnazio Danti, cosmographer to Cosimo I de’ Medici, installed the first meridian line there. Unfortunately it did not fulfill its purpose, which was to provide an accurate date for the spring equinox, thence Easter. In spite of uncertainties about the precise length of the solar year, the Gregorian calendar was promulgated anyway, in 1582. We still use it today. Almost 75 years later, the opportunity arose to reconstruct the meridian. Enter a 29-year-old astronomy professor named Giovanni Domenico Cassini. Cassini increased the height of Danti’s solar peephole—or gnomon hole—to 1000 inches (based on the French foot) or 27.07 meters above the church floor. The length of the meridian line was increased by x2.5 to 66.71 meters, or 1/600,000 of the Earth’s circumference, per Cassini’s calculation. The line had to run on the floor between the aisles and columns of the church on a north-south axis without obstruction. The instrument was tested with great fanfare at the summer solstice of 1655 and proved fully successful. Cassini’s illustrated account of his heliometer was published 40 years later in 1695 with the title La Meridiana del tempio di S. Petronio. The image shown here is taken from a large foldout plate depicting the design and details of installation.