

Dec. 28, 1888.] 



SCIENTIFIC NEWS. 



643 



the figures, and no less than eleven other marks, such 

 as £ % [ * ] an d six fractions, can be employed. The 

 type are arranged in three rows on two ebonite seg- 

 ments. Each of these resembles one-sixth part of a broad- 

 tyred wheel, with the type set like three rows of nails 

 around it. Each segment is attached to the centre by 



damage the machine by depressing more than one key 

 at a time. If several keys are depressed at once, the 

 type segment stops at the stop pin raised by the key 

 nearest the middle of the key-board,and the corresponding 

 letter is printed. 



The mechanism is most ingenious, and not only would 



Barlock Type-writer: Front View. 



five broad spokes. The segments lie wide apart when 

 at rest, and the act of depressing a key moves one of 

 them round, and at the same time raises a stop pin, 

 against which it comes to rest, the proper type being 

 then in position. Continuing the depression, a spacing 



Barlock Type-writer : Rear View. 



it be impossible to describe" it without drawings, but 

 when seen in operation, is rather difficult to understand. 

 The parts, however, are very strong, and require practic- 

 ally no oil. The alignment is perfect, since this merely 

 depends on the level to which the type segments are 



pi 



The Hammond Type-writer. 



hammer at the back of the machine is released, giving a 

 blow which is quite independent of the force with which 

 the key is depressed. The hammer is moved by the es- 

 capement action of the spring driving the carriage, which, 

 as in most type-writers, is wound up by the act of push- 

 ing it back to commence a new line. It is impossible to 



raised by depressing the " Cap." or " Fig." keys* 

 Another important advantage possessed by this machine' 

 is that the writing is visible up to the last two or thre e 

 words, the paper rising up immediately in front of th e 

 operator. Even this might be improved to allow th e 

 writing up to within nine or ten letters to be seen, by a 



