1723 in science

Geophysics

• George Graham discovers diurnal variation in Earth's magnetic field.
• Antoine de Jussieu publishes De l'Origine et des usages de la Pierre de Foudre on the origins of fossils, prehistoric stone tools and meteorites.

Optics

• Giacomo F. Maraldi makes the first observation of the Arago spot, unrecognized at this time.

Births

• January 5 – Nicole-Reine Lepaute, French astronomer (died 1788)
• January 31 – Petronella Johanna de Timmerman, Dutch scientist (died 1786)
• February 17 – Tobias Mayer, German cartographer, astronomer and physicist (died 1762)
• April 30 – Mathurin Jacques Brisson, French zoologist (died 1806)
• November 12 – Saverio Manetti, Italian natural historian (died 1785)

Deaths

• August 26 – Anton van Leeuwenhoek, Dutch pioneer of the microscope (born 1632)

References

References

1. Graham, George. (1724). "An Account of Observations Made of the Variation of the Horizontal Needle at London, in the Latter Part of the Year 1722, and Beginning of 1723". [[Philosophical Transactions of the Royal Society]].
2. Graham, George. (1724). "Observations of the Dipping Needle, Made at London, in the Beginning of the Year 1723". Phil. Trans..
3. "Les pierres de foudre".
4. Hecht, Eugene. (2002). "Optics". Addison Wesley.