ON GRArUIC MKTIIODS IN MECHANICAL SCIENCE. 325 



Smith, R. H. ' Graphic Calcalations.' Articles in The Engineer, 

 1883 and 1884 



Smith, R. H. ' Graphic Kinematics of Rigid Bar Mechanisms.' 

 Trans. R. Soc. Edin., vol. Ixxxi., 1885. 



Smith, R.H. 'Examples of Graphic Kinematics.' The Engineer, 

 vol. Ixi., p. 257, April, 1886. 



Smith, R. H. ' Graphic Diagram for Design of Slide Valves.' The 

 Engineer, November 5, 1886. 



Smith, R. H. ' Graphic Diagrams for Design of Boiler Heating 

 Surface.' Industries, July 8, 1887. 



Smith, R. H. ' Steam Curves and Expansion Curves.' Industries, 

 April and May, 1888. 



Smith, R. H. ' Graphic Investigation of Player's Pnenmatic Ham- 

 mer.' Engineering, June 20, 1884, vol. 37, p. 545. 



Smith, R. H. ' Graphics, or the Art of Calculation by Drawing 

 Lines, especially applied to Mechanical Engineering.' Longmans & Co. 



Smith, R. H. ' Graphic Construction for best Low Pressure Cut-ofF 

 in Compound Engines.' The Engineer, November 27, 1885. 



Steiner, Fr. ' Die graphische Zusammensetzung der Kriifte.' Vienna, 

 1876. 



Trautwine. ' Excavations and Embankments — Method of calculating 

 the cubic contents by the aid of diagrams.' AViley & Son, New York, 



Vose, G. L. ' Graphics.' Eclectic Engineering Magazine, (Van 

 Nostrand) New York, 1875 (12), 529. 



Vogler, C. A. ' Anleitnng zum Entwerfen graphisclier Tafeln.' 

 Berlin, 1877. 



Vfenck, J. ' Die graphische Statik.' Nicolai, Berlin, 1879. 



Weyrauch, Jakob J. ' Ueber die graphische Statik.' Leipzig, 1874. 



Wittmann, W. ' Die graphische Bestimmung der Maximalmomente 

 einfacher, durch bewegliche Lasten- Systeme beanspruchter Trjio'er.' 

 Munich, 1877. 



Willett, J. R. ' Some Applications of Graphical Statics.' (Am. Inst, 

 of Architects, Chicago, 1888.) 



Williot. ' Notions Pratiques sur la Statique graphique.' Paris, 1877. 



Woodbury, D. P. ' Sustaining Walls. Geometrical constructions to 

 determine their thickness under various circumstances.' Washinetou. 

 1854. ^ 



Graphical Methods in applied Electrical Science. 



In practical electrical science graphical methods have not as yet found 

 much favour. This is probably owing to the fact that most of the pro- 

 blems relating to electric lighting and telegraphy present no difficulties of 

 a mathematical character, and can be very readily solved by ordinary 

 numerical methods. There are, however, two cases in which the use 

 of a geometrical construction leads to a more direct solution. The 

 most important of these is the application of the characteristic curve of a 

 dynamo to questions connected with its working. 



(1) In the form originally suggested by Dr. J. Hopkinson' a character- 

 istic curve is one whose ordinates represent the electromotive force of a 

 dynamo running at any given speed, and whose abscissa) give the corre- 



' Hopkinsou, Proc. Inst. Mech. Eng., April 1879; ibid., April, 1880. 



