XXX1/ 



INTRODUCTORY CHAPTER. 



meridian passing through Paris ; that is to say, the ten-millionth part 

 of the distance between the equator and the pole, measured through 

 Paris. It is eq'ial to 393707898 inches. The metre is divided 

 into one thousand millimetres, one hundred centimetres, and 

 ten dfoiinltres ; while a decamttre is ten metres, a hectometre one 

 hundred metres, a kilometre one thousand metres, and a mi/riometre, 

 ten thousand metres. The following table gives the value of these 

 measurements in English inches anl yards : 



One English yard is equal to 0*91438 metre ; while one mile is equal 

 to 1-60931 kilometre. 



In the annexed woodcut a decimetre, with its divisions into 

 centimetres and millimetres, is shown, and compared with four inches 

 divided into eighths and tenths.. 



Unit of Surface. For the unit of surface, the square inch, foot, 

 and yard adopted in this country are replaced in the metric system 

 by the square millimetre, centimetre, decimetre, and metre. 



1 square metre 

 1 square inch 

 1 square foot' 

 1 square yard 



1-9160333 square yards. 

 6'4513669 square centimetres. 

 9-2899683 square decimetres. 

 0-83609715 square metre. 



