Logarithm Tables and Calculating Tools

Timeline

1. 1614Edinburgh · ScotlandJohn Napier published Mirifici Logarithmorum Canonis Descriptio, the result of about 20 years of research, systematically expounding the concept of logarithms: converting multiplication into addition and division into subtraction, accompanied by a table of logarithms of sines of angles, which immediately drew wide attention from European mathematicians.
2. 1617–1618London · EnglandHenry Briggs, mathematics professor at Gresham College, twice visited Napier in Edinburgh, and together they agreed to change the logarithm base to 10, so that log(1)=0 and log(10)=1; Napier died in 1617, and Briggs carried on his work, publishing that same year the first short table of common logarithms from 1 to 1000, Logarithmorum Chilias Prima.
3. 1620–1622London · EnglandIn 1620 Edmund Gunter designed a wooden scale marked with logarithmic divisions (Gunter's Scale), on which multiplication and division could be performed with dividers; around 1622 William Oughtred slid two Gunter scales back to back, inventing the prototype of the slide rule, which allowed direct calculation without dividers and became an iconic tool of scientific and engineering computation.
4. 1624London · EnglandHenry Briggs published Arithmetica Logarithmica, containing 14-digit common logarithms for 30,000 integers from 1 to 20,000 and from 90,001 to 100,000, presented in elegant print with detailed instructions; the book became the standard reference for scientists, navigators, and engineers for centuries, and Kepler used logarithm tables to accelerate his calculations of planetary motion.
5. 1628Harderwijk · NetherlandsDutch mathematician Adrian Vlacq filled the gap between 20,000 and 90,000 in Briggs's table, publishing a logarithm table covering all integers from 1 to 100,000, included in Arithmetica Logarithmica (Gouda edition); this complete table was soon translated into many languages, marking the full maturation of logarithm tables as a standard scientific tool, and remained in use until electronic computers became widespread in the twentieth century.