On Printing Presses and their Theory. 319 



prior inventions into the back ground, it must in its turn 

 yield to the progress of improvement. The points of supe- 

 riority in the Lever, over the Columbian press, appear to be 

 the following. 1 . It is afforded at two thirds of the expense. 



2. The mechanism is lighter, and more compactly stowed. 



3. From the greater simplicity of structure, it is less liable 

 to get out of repair, and is more easily put in order when 

 out of repair by a person of common mechanical skill. 4. 

 The surfaces which move in contact are so contrived as to 

 be kept oiled without being taken in pieces. Accordingly, 

 those who have had trial of both, so far as the writer can 

 learn, both owners and workmen, give the preference to the 

 Lever press. 



High as is the perfection to which this press has been 

 brought by its inventor, it would be strange if it were abso- 

 lutely incapable of improvement, or if farther experience 

 should not point out some changes for the better. Among 

 the infinite variety of which the adjustment of the levers is 

 capable, there can be but one which is absolutely the best^ 

 and it is scarcely supposable that this one has been yet at- 

 tained. A slight variation of the position and form of the 

 working parts in different successive castings, promises more 

 effectually than any thing else to make known those slight 

 improvements of which they may still be capable. Several 

 of the parts appear to possess superfluous strength. The 

 cheeks might probably be reduced to one half their present 

 size with advantage. The top and bottom of the frame 

 must be made strong, because they require to be incapable 

 of springing as well as of breaking. But v/hile this is the 

 case, the strain on the sides so far as it is produced by the 

 two main levers is wholly a longitudinal one, and the re-ac- 

 tion of the driving lever against the right side is comparative- 

 ly small. Admitting the re-action of the platen, in perform- 

 ing the heaviest work, to be thirty-five thousand pounds, the 

 two sides would possess sufficient strength to prevent their 

 being drawn asunder if made of sound cast iron three-fifths 

 of an inch square. But if reduced to one half their present 

 size, they would possess sixteen times this degree of strength. 

 The driving lever also, if made very nearly straight, as it 

 might be without interfering with the main levers, might be 

 diminished one half or two thirds in size. On other im- 

 provements of a more problematical character which have 

 suggested themselves, it will not be necessary to enlarge. 



