

The number and variety of problems that can be worked out with the aid of A. W. Faber's calculating rule 

 is almost endless, and so simple and expeditious is the mode of procedure that, with a little practice, the rule 

 I becomes a reliable and time-saving adjunct to all who are engaged in arithmetical work, no matter of what 

 l description. 



In order to render the construction and mode of employment of the rule intelligible even to those who possess 

 but a moderate amount of technical knowledge, a new book of instruction has been prepared, which will be found 

 a concise and practical guide to the use of the instrument, having special regard to English or American 

 requirements. 



The book consists of 35 pages of printed matter and 12 sheets of diagrams. 



The success which Faber's calculating rule, mentioned above, has met with, has led to further efforts being 

 made to bring this instrument as near to perfection as possible. 



A short treatise has been added to the book of instructions for the use of A. W. Faber's calculating rule, 

 which fully explains in detail the various improvements. 



m PAYfltGAlLWEYCOflPUWi DIALS 



(FULL* PROTECTED.) 





ijj** 



FRONT PACE. 



BACK FACE 





Front face. 



3212 



Back face. 



at 1,500 Ibs. per sq. 

 inches and fractions 



in. from 

 and vice 



J12 T The Payne-Gallwey Computing Dials .... 



With one setting of an indicating arm of this instrument for each of the following results the answer 

 > read off direct in plain figures over the top edge of the arm. 



In some cases three or more answers are given simultaneously with one setting of the arm. 



BACK FACE. 



Hydraulic powers 



diameters in 



versa. 

 Gallons contained in cylinders, pipes, pumps, etc., 



per foot run, from diameters in inches and 



fractions and vice versa. 

 Weight of gallons of water per foot run in above and 



vice versa. 



Pounds to the decimal of a cwt. and vice versa. 

 Quarters and pounds to the decimal of a cwt 



vice versa. 



Shillings to the decimal of a and vice versa. 

 Shillings and pence to the decimal of a pound and 



vice versa. 

 Cwts. to the decimal of a ton and vice versa. 



12 6 



FRONT FACE. 



inferences from diameters in inches and fractions 



and vice versa, 

 from diameters in inches and fractions and vice 



versa. 



ictres from inches and fractious and vice versa. 

 Centimetres from inches and fractions and vice versa. 

 Decimetres from inches and fractions and vice versa. 

 Parts of a metre from inches and fractions and vice 



versa. 



[Sovereigns and shillings to francs and vice versa. 

 Millimetres to the decimal of an inch and vice versa. 

 Decimals of an inch to fractions and vice versa. 

 Decimals of a foot to the fractions of an inch and vice 



versa. 



Decimals of a foot to inches and vice versa. 

 Decimal of a shilling to farthings and vice versa. 

 Decimal of a shilling to pence and vice versa. 



and 



