VIII. MACHINERY. 473 



2044a. Photograph of the original sketch of Nas- 

 myth's Steam Hammer. James Nasmyth. 



This rapid sketch made on the morning of November 24th, 1839, embodies 

 the original ideas of the invention of the steam hammer ; it contains the 

 main features and details, which have proved so satisfactory in practice as to 

 be retained to the present time. 



2045. Drawing of a 5O-ton Double-action Steam Ham- 

 mer, supplied to the Russian Government for their gun factory at 

 St. Petersburg. Thwaites and Carbutt. 



Diameter of cylinder, six feet, six inches ; length of stroke, twelve feet six 

 inches ; total height from ground line, fifty feet. 



Allen's Steam Striker. J. W. Thomas. 



2045a. Model of a Friction-Hammer. 



John Title, Prague. 



This model is 72 cm. high, 42 cm. broad, and 21 cm. in length, and has 

 been executed after the pattern of the friction-hammer constructed in the 

 Royal Prussian Machine Workshops at Dirschau, where the exhibitor, in 

 1858 and 1859, was employed with the construction of the incline between 

 Elbing and Osterrode. 



With reference to this model it is to be observed that the small cog wheels 

 fixed on the revolving shafts of the friction-rollers have only been attached 

 for the purpose of putting the model in motion with a crank. 



2045b. Model of a Spring or Elastic Hammer. 



John Tille, Prague. 



These favourite spring-hammers, if in quick motion, effect a very powerful 

 stroke ; if in slow motion, a moderate stroke, the regulation of which is 

 obtained by a treadle and a draw-pole, by means of a tension roller supported 

 by levers. If the movement is stopped, the tension roller acts as a brake- 

 weight. 



In recent times, spring-hammers of this form are manufactured by Messrs. 

 Auth. Fetn, and Deliege, at Liege. 



2045c. Model of a Punching Machine. 



John Tille, Prague. 



This model is constructed after Borsig's pattern, in which the balancing 

 ^unch is moved forwards by a crank and wheels, by means of a movable 

 press-bar. 



2O45d. Model of Parallel Shears. John Tille, Prague. 



The movable cutting blade is fastened to a well regulated sliding piece, and 

 moved by a crank and wheels by means of a draw-bar. This model is 

 arranged at the same time to be worked by means of leather straps. 



2O45e. Model of Circular Shears, with cast ribbed frame. 



John Tille, Prague. 

 2O45f. Model of Circular Shears, with concave cast frame. 



John Tille, Prague. 



These two models, the circular cutting blades of which are fastened on 

 spindles, and put in motion by means of wheels and cranks, illustrate chiefly 

 the solidity and elegance of the concave casting as compared with the ribbed 

 casting. 



