Arms are easy to draw when broken into parts. Draw straight or slightly bent lines from the shoulders downward. Split each arm into upper arm and forearm sections. Keep the arms relaxed and hanging ...

THE great geometrician Euclid, before demonstrating to us the various propositions contained in his “Elements of Geometry” requires that we should be able to effect certain processes. These Postulates ...

III. BEFORE leaving the Peaucellier cell and its modifications, I must point out another important property they possess besides that of furnishing us with exact rectilinear motion. We have seen that ...

If you enjoyed this article, I’d like to ask for your support. Scientific American has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in ...