vi CONTENTS. 



PACK 



odd numbers methods of remembering the lengths of the 

 months. 64. Calends. 65. Greek Calends. 66. Nones. 67. 

 Ides. 68. Practice of counting backwards. 69. Discordance of 

 the Roman year with the seasons. 70. Month Mercedonius. 

 71. Legal meaning of "month." 72. The year. 73. What is 

 a year ? 74. Egyptian. 75. Only a rude approximation to the 

 course of the seasons. 76. The vague year and Sothic period. 

 77. Advantage of Egyptian year. 78. Greek year. 79. Meton 

 and his cycle. 80. Origin of Golden Number. 81. Meton 

 ridiculed by Aristophanes. 82. Near accordance of the lunar 

 phases with the Metonic cycle. 83. Roman year. 84. Pontifical 

 abuses. 85. Julian Calendar. 86. Bissextile years . . . 145 



CHAP. IV. 87. Year of confusion. 88. New arrangement of the 

 months. 89. Mistake of the Pontiffs. 90. Leap-years. 91. 

 Historical dates. 92. Day of the equinox. 93. What is the 

 equinox? 94. The two equinoctial points. 95. Sidereal year. 

 96. Precession of the equinoxes. 97. Equinoctial year. 98. 

 Civil year. 99. Difference between it and the Julian year. 100. 

 Effect of this difference. 101. Cause of the reformation of the 

 Calendar. 102. Discordance between the real and ecclesiastical 

 equinox. 103. Gregorian reform. 104. Gregorian Calendar. 

 105. Its compensating effect. 106. Resistance to its adoption. 

 107. Dates of its adoption in different countries. 108. In 

 England. 109. Its reception there. 110. Occasional agreement 

 of the new and old styles. 111. Anecdotes relating to the 

 change. 112. Russia adheres to the old style. 1 13. Commence- 

 ment of the year. 114. Various in different countries. 115. In 

 England. 116. Old and new style in England. 117. Temporary 

 inconvenience attending it 161 



COMMON THINGS. PUMPS. 



1. Earliest methods of raising water. 2. Bucket in a well. 3. By 

 windlass and rope. 4. By two buckets balanced over a pulley. 

 5. Method of working these by animal power. 6. The rope in 

 this case balances itself. 7. The lifting pump. 8. Double 

 lifting pump worked by animal power. 9. Various forms of 

 valves. 10. Clack valves. 11. Conical spindle valves. 12. 

 Ball valves. 13. The suction pump. 14. Analysis of its action. 

 15. Forcing pump. 16. Same with air vessel. 17. Same with 

 solid plunger. 18. Double action forcing pump. 19. Garden 

 watering pumps. 20. Fire-engine. 21. Chain pump. 22. 

 Drainage of mines 177 



COMMON THINGS. SPECTACLES. 



1. Their general utility. 2. Should therefore be generally understood. 

 3. Vision. 4. Blindness. 5. Defective sight. 6. Long and 

 short sight. 7. Remedy. 8. Spectacles. 9. Effect of convex 

 lenses. 10. Of concave lenses. 11. Focal length of a lens. 12. 





