j6 SCIENTIFIC APPARATUS. 



Thus in solid machinery we have 



i. Prime movers. 



2. Trains of mechanism. 



3. Fixed framework. 



4. Fly-wheels, springs, weights raised. 



5. Friction breaks. 

 6. Governors, pendulums, balance springs in watches. 



7. Dynamometers, Strophometers, Watt's indicator, chrono- 

 graphs, &c. 



8. Scales for these indicators. Standards of length and 

 mass. Astronomical standard of time. 



For the phenomena depending on fluid pressure we have 



i. Pumps, condensing and rarifying syringes, Orsted's 

 Piezometer, Andrews's apparatus for high pressure. 



2. Pipes and tubes. 



3. Packing, washers, caoutchouc tubes, paraffin joints ; 

 fusion and other methods of making joints tight. 



4. Air chambers, water reservoirs, vacuum chambers. 



5. Safety valves. 



6. Governors by Siemens and others, Cavaille'-Col's regu- 

 lator for organ blast. 



7. Pressure-gauges, barometers, manometers, sphygmo- 

 graphs, &c. ; areometers, and specific gravity bottles ; 

 current meters, gas meters. 



8. Scales for these gauges. 



For thermal phenomena 



i. Furnaces, blow-pipe flames, freezing mixtures, solar and 

 electric heat. 



2. Hot water pipes, copper conductors. 



3. Non-conducting packing, cements, clothing, &c. ; steam- 

 jackets, and ice-jackets. 



4. Regenerators, heaters, &c. 



