a a ef 
= tion, it is necess 
Hough—Description of a Printing Chronograph. 437 
of an apparatus designed for this purpose, and about the same 
time Prof. C. A. Young, of Dartmouth College, published a 
proposed plan for one,* But, so far as we are informed, the 
mechanical construction of such an apparatus has not hereto- 
fore been attempted by any one. 
The construction of a machine which shall carry a type 
wheel, capable of giving impressions, with uniform ve ocity for 
anumber of hours together, without sensible variation in its 
motion, is a problem which is not easy of solution. 
me five or six years ago, in a paper read before the Albany 
Institute, I gave an account of the method I proposed to adopt, 
and in the construction of the machine, now to be described, 
the plan then proposed has been generally followed. My plan, 
which is radically different from any other proposed, is based 
on the principle of using separate systems of mechanism for 
the fast-moving type wheel, and those recording the integer 
minutes and seconds, regulating each with electro-magnets 
controlled by the standard clock. 
_ Hor a clear understanding of the mechanism, elaborate draw- 
ings would be necessary. We shall, therefore, merely give a 
general account of its construction and peculiarities : ; 
Ist. A system of clock-work carrying a type wheel, with 
fifty numbers on its rim, revolving once every second; one, 
two, or parts of two numbers being always kag: so that 
nd. A system of clock-work, consisting of two or more 
shafts, carrying the type wheels indicating the minutes and 
seconds. ‘The motion of this train is also governed by an elec- 
he type wheels are constructed of brass disks, around the 
circumference of which is soldered a strip of electrotype copper, 
holding sixty numbers. is 
Presuming now we have this system of type wheels in opera- 
essary to print without disturbing their motion; 
* See this Journal, No. 124, July, 1866. 
