{{short description|Builder's instrument for measuring inclination}} [[File:L' Inde Française24.jpg|thumb|{{center|Indian mason at work using an archipendulum<br>from ''L'Inde française''}}]] thumb The '''archipendulum''' is an ancient ancestor of the spirit level and astrolabe, and was used to check whether a line was horizontal or at a desired inclination. It consisted of a handheld A-shaped construction with a plumbline suspended from the top vertex. The horizontal bar of the A was marked at its midpoint, so that the plumbline's coincidence with this point indicated that the bases of the two legs were at the same level. Other gradations on the horizontal bar enabled the user to construct or verify inclined lines. The same methods of use apply to the inverted 'T' which is simply another variant of the archipendulum.
Used by the builders of the Egyptian pyramids and from the Indian subcontinent, it was more recently described by Johann Heinrich Alsted<ref name="google">{{cite book|title=Johannis-¬Henrici Alstedii compendium philosophicum: exhibens methodum, definitiones, canones, distinctiones & quaestiones per universam philosophiam ...|author=Alsted, J.H.|date=1626|publisher=Corvinus & Muderspach|url=https://books.google.com/books?id=Hsk-AAAAcAAJ|accessdate=2015-08-02}}</ref> and Leon Battista Alberti.<ref name="google2">{{cite book|title=The Mathematical Works of Leon Battista Alberti|author1=Williams, K.|author1-link=Kim Williams (architect)|author2=March, L.|author3=Wassell, S.R.|date=2010|publisher=Springer Basel|isbn=9783034604741|url=https://books.google.com/books?id=NBAKwthCGLUC|accessdate=2015-08-02}}</ref>
{{commons category|Archipendula}}
==External links== *[https://web.archive.org/web/20110827134357/http://puffin.creighton.edu/museums/cohagan/egypt_build.htm Building the Pyramids]
==References== {{reflist}}
Category:Inclinometers