Pressure measurement--Clark cell--Weston cadmium cell--pressure measurement error with ordinary voltmeter--International volt--hydraulic analogy of amperes--coulombs--current measurement--International ampere--voltameters--Ohm's law and the ohm--International ohm--ohm table--practical standards of resistance--various methods of resistance measurement--direct deflection method--method of substitution--resistance box--fall of potential method--differential galvanometer method--drop method--voltmeter method--Wheatstone bridge--usual arrangement of resistances of Wheatstone bridge--ratio coils of Wheatstone bridge--the decade plan--two plug arrangement--"plug out" and "plug in" type of resistance box--testing sets--direct deflection method with Queen Acme set--ohmmeter--fall of potential method with Queen Acme set--apparatus for measuring low resistances--how to check a voltmeter--Kelvin wire bridge--internal resistance measurement--Evershed portable ohmmeter set--L and N fault finder--ammeter test--diagram of Queen standard potentiometer--diagrams illustrating loop testing--the Murray loop--the Varley loop--special loop--the potentiometer--location of opens--to pick out faulty wires in a cable--voltage of cell measurement with potentiometer--care of potentiometer--location of faults where the loop is composed of cables of different cross sections. AMMETERS, VOLTMETERS, AND WATTMETERS 537 to 572 Definition of ammeter--classification of ammeter and voltmeters--moving iron type instrument--Keystone voltmeter--winding in ammeters and volts--connections for series and shunt ammeters--voltmeter connections--Westinghouse ammeter shunts--various types of instrument--plunger type instrument--magnetic vane instrument--inclined coil instrument--Whitney hot wire instruments--principle of electrostatic instruments--multipliers--portable shunts--Siemens electro-dynamometer--station instruments--Thompson watt hour meter--how to read a meter--installation of wattmeters--Westinghouse watt hour meter--Thompson prepayment watt hour meter--how to test a meter--Sangamo watt hour meter--Columbia watt hour meter--Duncan watt hour meter. OPERATION OF DYNAMOS 573 to 596 Before starting a dynamo--adjusting the brushes--brush position--how to set the brushes--method of soldering cable to carbon brush--brush contact pressure--direction of rotation--method of winding cables with marlin--method of assembling core discs--starting a dynamo--tinning block for electric soldering tool--shunt dynamos in parallel--shunt dynamos on three wire system--how to start a series machine--the term "build up"--how to start a shunt or compound machine--"picking up"--indication of reversed connections--how to correct reversed polarity--finding the reversed coil--loss of residual magnetism--remedy for reversed dynamo--attention while running--lead of brushes--method of taking temperature--lubrication--oils--allowable degree of heating--attention to brushes and brush gear.