Page 14 - February 2018
P. 14

83        +3    84         +2,-4   52         +2     83         +3     50        +2,-4
   Bi               Po                 Te                Bi                Po
       FEATURE
       FEATURE BOB RICHARDSON 9718BOB RICHARDSON 9718
  Bismuth          Polonium           Tellurium         Bismuth           Polonium
   208.980           208.982             127.6           208.980           208.982

 33       +5,-3   31        +4,-2   32         +4     33        +5,-3   34        +4,-2
  Zn                Ga                Ge                As                 Se



    Zinc            Gallium         Germanium            Arsenic          Selenium
    74.922            69.723            72.631            74.922            78.971
 51        +3    82          +2    50         +2,-4   51         +3     53         +2
   In               Pb                Sn                Sb                   I



   Indium             Lead               Tin            Antimony           Iodine
   121.760            207.2             118.711           121.760          126.904.2

 83        +3    84         +2,-4   52         +2     85         +3     86        +2,-4
   Bi               Po                 Te                At               Rn



  Bismury          Polonium           Tellurium         Astatine           Radon
   208.980           208.982             127.6           210.350           208.982

 33       +5,-3  34         +4,-2   32         +4     33        +5,-3   34        +4,-2
        HOW HARD IS ‘HARD’?
  As                Se                Ge                As                 Se


  Arsenic PART TWO: TYPE METAL COMPOSITION                                Selenium
                    Selenium
                                    Germanium
                                                         Arsenic
    74.922            78.971            72.631            74.922            78.971
           he miraculous type-metal alloy dis-  used much harder alloys than recom-
                 82
 51    Tmay have been known to Gutenberg,    mended by the Monotype Corporation:   +2
                                                                        82
                                                      51
                                   50
           cussed in last month’s Small Printer
                             +2
                                                                 +3
                                              +2,-4
           +3
                                             Startype in Birstall was once known for
  Sb                Pb                Sn                Sb                Pb
       who had some training as a goldsmith and
                                             the quality of its ‘Diamond’ types, which
       was a skilled metallurgist by the time he
                                             contained more tin and antimony than
       turned his mind to the problem of finding
 Antimony             Lead               Tin  standard Monotype.            Lead
                                                        Antimony
       a suitable printing metal in the mid-15th
                                              Type metal is a eutectic alloy, which
       century. The basic formula has remained
                                                          121.760
   121.760            207.2             118.711 essentially means that the trio of metals  207.2
       relatively unchanged for five centuries, but   melts at a significantly lower temperature
 83    the proportions vary, according to the end   than the melting point of antimony (the   +2,-4
                                             hardest ingredient, which normally melts
       use of the type. Some Monotype foundries
       38
   9   10   11   12   13   14   15   16   17   18   19