1. A high speed digital fluidic computer for use in a material handling device, the computer comprising: means for generating a first signal comprising repetitive fluidic pulses, the cumulative quantity of which represents a first variable to be entered into a computation; means for providing a second signal comprising a persistent fluidic representation of a second variable to be entered into said computation by repetitive addition, said second signal providing means including material quantity detecting means and operating to generate said second signal once for each predetermined unit quantity of material detected by said detecting means; and fluidic calculating means arranged to retain a total and responsive to said first and second signals to increment said total by the amount of said second variable for each of said first signal pulses.

2. A high speed digital fluidic computer for use in a material handling device, the computer comprising: means adjustable for selecting a number; a digital fluidic calculating circuit having a plurality of digital fluidic signal inputs; number-representing means responsive to said number selecting means to present a digital fluidic signal representing said number to a first one of said calculating circuit inputs; and means for repetitively generating a fluidic ''''add'''' signal and applying it to a second one of said calculating circuit inputs, said ''''add'''' signal generating means including material quantity detecting means and operating to generate said ''''add'''' signal once for each predetermined unit quantity of material deTected by said detecting means; said calculating circuit being arranged to accumulate and retain a total, and being responsive to each ''''add'''' signal to add to its current total the number represented by the signal presented to said first input.

16. A high speed digital fluidic computer for use in a material handling device, the computer comprising: means adjustable for selecting each digit of a number having a plurality of digit positions when represented in a nonbinary number system; a plurality of independently operable binary-coded digital fluidic calculating circuits corresponding to respective ones of said non-binary digit positions, and each having a plurality of binary-coded digital fluidic signal inputs; means responsive to said number selecting means to present respective binary-coded digital fluidic signals, representing the respective non-binary digits assigned to said digit positions by said number selecting means, to respective first ones of said digit position calculating circuit inputs; means for repetitively generating a fluidic ''''add'''' signal and applying it to respective second ones of said digit position calculating circuit inputs, said ''''add'''' signal generating means including material quantity detecting means and operating to generate said ''''add'''' signal once for each predetermined unit quantity of material detected by said detecting means; said digit position calculating circuits being arranged to accumulate and retain respective totals, and being responsive to each ''''add'''' signal to add to their respective current totals the respective non-binary digits represented by the signals presented to their respective first inputs; means providing said digit position calculating circuits with respective digital fluidic external carry outputs; and each more significant one of said digit position calculating circuits having a third one of said inputs connected to said external carry output of the next less significant digit position calculating circuit, and being arranged to increment its current total by the quantity one for each external carry signal received.

17. In a device for transferring flammable material; a high speed digital fluidic cost computer for calculating the cost of material transferred, comprising: means adjustable for selecting a number having a plurality of decimal digit positions, and representing the cost of a predetermined unit quantity of said material; a plurality of independently operable digital fluidic decade cAlculating circuits corresponding to respective decimal digits of said cost, and each having a plurality of digital fluidic signal inputs; digital fluidic encoding means responsive to said cost selector to present repsective binary-coded fluidic signals, representing respective decimal digits of said cost, to respective first ones of said decade circuit inputs; a material quantity detector arranged to detect each unit quantity of said flammable material transferred; means responsive to said detector to generate a fluidic ''''add'''' signal for each unit quantity of said flammable material transferred, and to apply said ''''add'''' signal to respective second ones of said decade circuit inputs; said decade circuits being arranged to accumulate and retain respective totals, and being responsive to each ''''add'''' signal to add to their respective current totals the respective decimal digits represented by the fluidic signals presented to the respective first inputs thereof; and means providing said decade circuits with respective fluidic decimal carry outputs; each said more significant decade circuit having a third one of said inputs connected to said decimal carry output of the next less significant decade circuit, and being arranged to increment its current total by the quantity one for each decimal carry output received.

20. In combination with a device for dispensing flammable fluid, a high speed digital fluidic cost computer for calculating the cost of fluid dispensed, comprising: means on said dispensing device adjustable for selecting a number having a plurality of decimal digit positions, and representing the cost of a predtermined unit quantity of said fluid; a plurality of independently operable digital fluidic decade calculating circuits corresponding to respective decimal digits of said cost, and each having a plurality of digital fluidic signal inputs; digital fluidic encoding means responsive to said cost selector to present respective binary-coded fluidic signals, representing respective decimal digits of said cost, to respective first ones of said decade circuit inputs; a flowmeter arranged to detect each unit quantity of said flammable fluid dispensed by said device; means responsive to said flowmeter to generate a fluidic ''''add'''' signal for each unit quantity of said flammable fluid dispensed and to apply said ''''add'''' signal to respective second ones of said decade circuits inputs; said decade circuits being arranged to accumulate and retain respective totals, and being responsive to each ''''add'''' signal to add to their respective current totals the respective decimal digits represented by the fluidic signals presented to the respective first inputs thereof; means providing said decade circuits with respective fluidic decimal carry outputs; each said more significant decade circuit having a third one of said inputs connected to said decimal carry output of the next less significant decade circuit, and being arranged to increment its current total by the quantity one for each decimal carry output received; means on said dispensing device responsive to said cost selector to display a unit cost corresponding to the number selected thereby; and a digital fluidic decimal counter on said dispensing device for accumulating and displaying cost, said counter being responsive to fluidic carry pulses; the most significant one of said decade circuits being arranged to supply its decimal carrY outputs to drive said counter.