Dec. 28, 1888.] 



SCIENTIFIC NEWS. 



645 



to which makers of type-writers should turn their atten- 

 tion. Inking tapes are sold which give a capital black 

 impression, but which will not copy; while the copying 

 tapes, though giving a good and indelible colour after 

 being copied, are both faint and easily smudged if not 

 copied. 



The Hall type-writer was one of those which suf- 

 fered at first from being placed in the market before it 

 was ready, though it was more complete when first in- 

 troduced into this country than some of those which we 



are being pressed on the ink pad. The result is that if 

 the same character be printed several times in succes- 

 sion, impressions rapidly become faint. In practice this 

 inconvenience is not often felt, but the machine will not 

 print "1,000,000" without a good deal of trouble with 

 the inking of the " o." 



type plate is controlled by a 



hinged handle which carries a 



handle therefore carries with 



the limits of an index plate. 



The mution of the 

 bar, furnished with a 

 conical pointer. The 

 it the type within 



The Columbia Type writer. 



have already described. Several improvements have 

 been effected which no doubt make it a more durable 

 machine than the two specimens which the present 

 writer used daily for several years. The first one be- 

 coming worn out, there was no way of having it repaired 

 but sending part of it back to America, but another ma- 

 chine was found also sadly out of order, and between the 

 two a new one was patched up. 



As in the Columbia, the paper remains stationary 

 during the printing of each line, while the upper part of 



In this plate are nine rows of nine holes, cor- 

 responding to the arrangement of the type. At the 

 bottom of each hole appears a letter. When the conical 

 pointer is pressed into any hole, the type corresponding 

 to the letter is brought opposite the square hole in the 

 inking pad. On applying pressure, the whole carriage 

 is depressed on to the paper, and the soft rubber of 

 which the type plate is composed, allows the proper 

 type to protrude through the hole. On the under side 

 of the cover or lid of the carriage is a flat-headed pin, 



The Hall Type-writer. 



the machine moves step by step to the right. The types 

 are formed of soft rubber on the face of a sheet of that 

 material, being arranged in nine rows of nine characters. 

 The plate is attached to a system of link work forming a 

 double parallel motion. The plate can thus be moved 

 in any direction, but always remains parallel to itself. 

 Beneath the type plate, that is, between the plate and 

 the paper, is an inking pad, which can be lifted out. In 

 the centre of the pad is a square hole, through which 

 one type at a time can be pressed on to the paper 

 benaeth. At each stroke, therefore, all the other type 



which is fixed exactly opposite the square hole : this gives 

 the pressure on the type. 



It might be supposed, not only from this description, 

 but from a trial of the machine, that it would be im- 

 possible to write at any considerable speed. While not at- 

 tempting to rival the key machines, there is little difficulty 

 in attaining forty words per minute, after several months' 

 use ; but it is necessary to have a very good light. 

 Plenty of light is needed for working any type-writer in 

 comfort, but for the Hall it is specially necessary, 

 since the letters are at the bottom of holes in the index- 



