120 ANNUAL REPORT SMITHSONIAN INSTITUTION, 1907. 
The justification is no less ingenious. The lines are composed with 
elastic spaces and are always a little too long. In shortening the line 
to the required length, each space is contracted, which is made possible 
by its compressibility. A quarter turn of the wheel brings the justi- 
fied line to the casting pot. At the same time collector I receives the 
cast line, the line in collector IT is justified, and collector IIT receives 
the series of matrices forming a third line. Finally a last quarter of 
a turn carries the matrices of the first composed line, previously free 
from the cast line, to the height of the vertical diameter, where they | 
are distributed in the magazine for further composition. The same 
successive rotation by a quarter of a turn continues, so that when the 
machine is in operation, while one line is being composed, the preced- 
ing one is justified, the one before that is cast, and the matrices of the 
previous one distributed. 
One of the advantages of the rototype is that the melting pot is 
placed as far as possible from the operator. 
The distribttion of matrices is simplified by the use of disks analo- 
gous to the die of the electrotypograph; but with ten characters 
instead of three. Thus, on the circumference of the same disk are 
associated the matrices of letters of the same thickness, capitals 
G, M, W, . . . small straight letters, i, 1, t, !, . . . and small letters 
of equal thickness, d, c,e, ... All disks of the same thickness and 
with the same letters have the same compartment in the magazine. 
The machine in freeing them threads them around an axle, to which 
they become attached only when the desired letter has reached the 
vertical position. 
The rototype can compose 6,000 characters per hour and requires 
only one-eighth of a horsepower for its operation. * * * 
The 1907 model of the rototype has no wheel, properly speaking, 
but has three arms with only three matrix carriers. These are 
hinged, and thus simplify corrections. The keyboard of the latest 
model has 100 keys, with 400 roman and 400 italic matrices. The 
face of the character is deeper than that of the linotype. Finally, 
. the machine, which weighs about 450 kilograms, occupies only a 
small space, being 1.40 m. in length, 0.85 m. in width, and 1.50 m. 
in height. . 
(B) MACHINES CASTING SINGLE TYPE. 
To avoid the disadvantages of slug-casting machines, a second 
class has been devised. ‘These machines compose with movable char- 
acters cast to measure and assembled in justified lines by means of 
spaces cast to measure with dimensions calculated in advance. ‘This 
machine performs the same work as the compositor at the case, omit- 
ting none of the successive steps, but enormously increasing the 
