- published: 19 Apr 2015
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A blueprint is a type of paper-based reproduction usually of a technical drawing, documenting an architecture or an engineering design. More generally, the term "blueprint" has come to be used to refer to any detailed plan.
Various base materials have been used for blueprints. Paper was a common choice; for more durable prints linen was sometimes used, but with time, the linen prints would shrink slightly. To combat this problem, printing on imitation vellum and, later, polyester film (Mylar) was implemented.
In 1861 Alphonse Louis Poitevin, a French chemist, found that ferro-gallate in gum is light sensitive. Light turns this to an insoluble permanent blue. A coating of this chemical on a paper or other base may be used to reproduce an image from a translucent document.
The ferro-gallate is coated onto a paper from aqueous solution and dried. The coating is yellow. In darkness it is stable for up to three days. It is clamped under glass and a light transmitting document in a daylight exposure frame, which is similar to a picture frame. The frame is put out into daylight requiring a minute or two under a bright sun or about ten times this under an overcast sky. Where ultra-violet light is transmitted the coating converts to a stable blue or black dye. The image can be seen forming, when a strong image is seen the frame is brought indoors and the unconverted coating, under the original image, is washed away. The paper is then dried.
Major is a rank of commissioned officer, with corresponding ranks existing in many military forces. It is also used in some police forces such as the New York State Police, New Jersey State Police and several others.
When used unhyphenated, in conjunction with no other indicator of rank, the term refers to the rank just senior to that of an army captain and just below the rank of lieutenant colonel. It is considered the most junior of the field ranks. In some militaries, notably France, the rank is referred to as commandant, while in others it is known as captain-major. It is also used in some police forces and other paramilitary rank structures.
When used in hyphenated or combined fashion, the term can also imply seniority at other levels of rank, including general-major or major general, denoting a mid-level general officer, and sergeant major, denoting the most senior NCO of a military unit.
It can also be used with a hyphen to denote the leader of a military band such as in pipe-major or drum-major.