JASON DePARLE 2013年8月3日 德克萨斯州加尔维斯顿——安吉莉卡·冈萨雷斯(Angelica Gonzales)在高中时走的是“哥特路线”——黑靴子、链条和工装裤——她的优等生身......

Sketch of Invented by Charles Babbage By L. F. MENABREA of Turin, Officer of the Military Engineers from the Bibliothèque Universelle de Genève, October, 1842, No. 82 With notes upon the Memoir by the Translator ADA AUGUSTA, COUNTESS OF LOVELACE http://www.fourmilab.ch/babbage/sketch.html Those labours which belong to the various branches of the mathematical sciences, although on first consideration they seem to be the exclusive province of intellect, may, nevertheless, be divided into two distinct sections; one of which may be called the mechanical, because it is subjected to precise and invariableRead More

  Difference Engine 3. (click for larger image) (note:detail theory here, http://robroy.dyndns.info/collier/ch3.html) History Before the day of computers and pocket calculators all mathematics was done by hand. Great effort was expended to compose trigonometric and logarithmic tables for navigation, scientific investigation, and engineering purposes. The larger efforts involved rooms of semi skilled people, called ‘computers’, capable of doing reliable arithmetic who would be under the direction of a skilled mathematician. In the mid-19th century, people began to design machines to automate this error prone process. Many machines of various designsRead More