ORGAN I Z 

 "KNOWLEDGE 



STORY 

 AND' PICTURE 



Qq 



Q is the seventeenth letter of the English alpha- 

 bet. In the original Phoenician from which the 

 letter was taken its name was qoph, which meant 

 ht ad, and in form it was a rude sketch of the back 

 of the head and neck nothing more than a circle 

 with a short, vertical line running through it. It 



represented a somewhat different sound from the kaph, from which modern k is taken; 

 but when the Greeks took over the alphabet they had no sound for it, and it fell into 

 disuse. The Romans, on the other hand, adopted it and made use of it in combination 

 with u, as it is used in English to-day. In reality, it is an entirely superfluous letter in Eng- 

 lish, for its place could be filled by kw in all ordinary words, as queen, and by k alone 

 in such occasional words from the French as coquettish. Q exists in English, therefore, 

 solely because the Phoenicians had need of it to represent a sound distinct from k. 



QUADRANT, kwod'rant, an instrument for- 

 merly used in navigation and in surveying for 

 ascertaining the altitude of the sun. The name 

 was given it because the instrument embodied 

 an arc of 90, or one-fourth of a circle. It has 

 been almost entirely superseded by the sextant 

 (which see). 



QUADRILATERAL, kwod ri lat ' er al, a plane 

 figure bounded by four straight lines. A quad- 

 rilateral whose opposite sides are parallel is a 

 parallelogram. Its opposite sides being parallel, 

 it follows that they are equal, and that its 

 opposite angles are equal. If the angles of a 

 parallelogram are right angles, the figure is a 

 rectangle; if the sides of a rectangle are equal, 

 the figure is a square. A parallelogram whose 

 opposite sides (only) are equal and whose an- 

 gles are oblique (not right angles) is a rhom- 

 hoid. When all the sides of a parallelogram 

 are equal and its angles are oblique angles, the 

 figure is a rhombus. 



A quadrilateral having only one set of paral- 

 lel sides is a trapezoid. If the nonparallel sides 

 are equal, the trapezoid is isosceles. A quadri- 

 lateral having no sides parallel is a trapezium. 



Trapezoid and Trapezium. Mathematicians 

 do not agree on the meaning of these two 

 terms. The above definitions are those ac- 

 cepted generally in the United States to-day, 



while in England the quadrilateral having two 

 parallel sides is called a trapezium and tho 

 quadrilateral having no parallel sides is called 

 trapezoid. The terms are often used inter- 

 changeably in the United States. A leading 

 writer defines a trapezoid as "a quadrilateral 

 having one pair of sides parallel," and then 

 adds, "It is seen by this that a parallelogram 

 is a trapezoid." 



Related Subjects. The reader is referred to 

 the following articles in these volumes 

 Mensuration Square 



Rectangle Trapezium 



Rhombus 



QUADRILLE , kwah dril', the name of a dance 

 of French origin, usually danced by four cou- 

 ples in a hollow square. It was introduced into 

 England in 1815, and from that country into 

 the United States, where it succeeded the 

 stately minuet, and at once became immensely 

 popular. First danced in ballets by groups of 

 four, eight or twelve all similarly dressed, it 

 was taken up by society and no ball was con- 

 sidered complete without the quadrille. There 

 are five distinct evolutions or figures performed 

 in turn by each of the four couples. The five 

 figures were given appropriate names, which of 

 course often varied in different places, the 

 original names being Le Pantalon, 1'Ete, La 



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