The first recorded observation of the transit of Venus

On November 24, 1639 (according to the calendar in use then), the transit of Venus was recorded for the first time by English astronomer Jeremiah Horrocks. A.S.Ganesh tells you more about Horrocks, a forgotten genius who died rather young…

Imagine yourself in a mathematics class. The teacher is working out a problem on the board, and deftly arrives at an answer and starts explaining it to the class. Even while they were at it, you noticed that a mistake had been committed along the way, thereby arriving at an erroneous answer. Would you raise your hand, stand up, and tell the teacher that they’ve made a mistake?

Doing that – even though it is the right thing – is not easy. We can go so far as to say that it is rather difficult. While good teachers would accept their mistake openly and go on to correct it, the chance of the teacher holding a grudge against a student for pointing out such mistakes is also not unheard of. After all, teachers are also humans, often with their own imperfections.

Imagine then if someone in their late teens or early twenties had to point out the mistakes in calculations of someone considered one of the greatest mathematicians – not just of his age, but all time. Even though German astronomer and mathematician Johannes Kepler had just passed away in the preceding years, it didn’t make the task of pointing out a mistake in his calculations any easier for English astronomer Jeremiah Horrocks. 

Born in 1618 at Toxteth, 5km from Liverpool, Horrocks was the son of a watchmaker and was largely self taught in his early years. He had a love for studying natural phenomena, but lack of proper books and instruction in mathematics meant that he didn’t have everything he required to take things forward. In 1632, still in his early teenage years, Horrocks therefore set out for Emmanuel College, Cambridge – by foot from Lancashire to Cambridge! He put himself through that journey of over 350 km with the objective of studying the stars.

His limited means meant that Horrocks had to work as a sizar (a student who receives an allowance toward college expenses and who originally acted as a servant to other students in return for this allowance) while studying at Cambridge. This included serving fellow students with their needs, and even emptying their bedpans if need be, to pay his way. 

Horrocks left without a degree, and there are rumours that that was because he’d run out of things to read at Cambridge! At 17, he became a tutor at Toxteth and two years later he was appointed curate at Hoole, near Preston. 

By 1638, Horrocks went further along his dream of studying the stars as he finally possessed a new telescope. Having had to limit his astronomy work with a more primitive instrument, the telescope, which was only decades old at that time, emboldened him to reach for the stars.