You are the Google search engine.
Given a query, you need to generate five useful documents for the query.

The user is trying to answer the question: "who invented the first gear driven calculating machine?" whose answer is Wilhelm Schickard.
Each document should contain about 30 words, and these documents should contain useful information.

Query: invention of the first gear-driven calculating machine
Useful Output:

Doc 1: In 1623 a new calculating device is discovered. Calculating clock: It is the first gear driven calculating machine[3]. It is invented by the German
Doc 2: In 1671 the German mathematician-philosopher Gottfried Wilhelm von Leibniz designed a calculating machine called the Step Reckoner. (It was
Doc 3: The first gear-driven calculating machine to actually be built was probably the calculating clock, so named by its inventor, the German
Doc 4: The first gear-driven calculating machine to actually be built was probably the calculating clock, so named by its inventor, the German
Doc 5: Between 1642 and 1644, Pascal conceived and constructed a calculating device, the Pascaline, to help his father—who in 1639 had been appointed