Scientific communication gains a dated public record

Jeremiah Horrocks predicted and observed Venus crossing the Sun; William Crabtree made an independent observation nearby.

Horrocks revised existing astronomical tables and used mathematical reasoning to predict a transit others had not expected.

Later astronomers used Venus transits and geometry to estimate the scale of distances between Earth, Venus and the Sun.

Horrocks and Crabtree worked outside major academies, showing that knowledge circulated through correspondence and local observation as well as institutions.

Henry Oldenburg launched a periodical that created a regular printed channel for reports in mathematics and natural philosophy.

Problems, observations, instruments and calculations could circulate more rapidly than through large books alone.

Its global reports often depended on colonial travel and unequal access; readers should distinguish wide geographic reach from equal participation.

Leibniz presented a model of his stepped reckoner to the Royal Society, aiming to mechanize repeated arithmetic.

The design could support addition, subtraction, multiplication and division through controlled movement of gears.

The machine sought to transfer routine calculation from human operators to a device, anticipating later debates about automation.