%  This procedure contains the information for the first page of information
%  dealing with the 'Thomson's Model' option.
procedure thom_page_1
    if flag not= 0 then
	openpage
    end if
    drawbox (0, 0, maxx, maxy, 2)
    color (2)
    locate (9, 37)
    put "EXPLANATION OF THOMSON'S MODEL"
    color (3)
    locate (11, 27)
    put "  J. J. Thomson proposed this model to explain the"
    locate (12, 27)
    put "arrangement of protons and  electrons in the atom."
    locate (13, 27)
    put "He considered the atom  to be a  sphere of uniform"
    locate (14, 27)
    put "positive  electricity in which  negatively charged"
    locate (15, 27)
    put "electrons  were  embedded like  raisins  in a plum"
    locate (16, 27)
    put "pudding.   Protons  had  more mass than electrons,"
    locate (17, 27)
    put "therefore  most  of the atom's mass was thought to"
    locate (18, 27)
    put "be associated with the positive charge."
    locate (23, 50)
    color (2)
    put "-1-"
end thom_page_1

%  This procedure contains the information for the second page of information
%  dealing with the 'Thomson's Model' option.
procedure thom_page_2
    openpage
    color (2)
    locate (9, 37)
    put "      THE DISCHARGE TUBE"
    color (3)
    locate (11, 27)
    put "A discharge tube consists of two electrodes sealed"
    locate (12, 27)
    put "into the ends of a glass tube.   These electrodes,"
    locate (13, 27)
    put "called the cathode (negative) and anode (positive)"
    locate (14, 27)
    put "are attached  to a high  voltage source.  When the"
    locate (15, 27)
    put "electricity is  turned on  and most of  the air is"
    locate (16, 27)
    put "pumped out,  current flows  between the electrodes"
    locate (17, 27)
    put "and the remaining air  in the tube begins to glow."
    locate (18, 27)
    put "If another gas is present in the tube besides air,"
    locate (19, 27)
    put "then a different colour glow appears. For example,"
    locate (20, 27)
    put "neon gas gives off an  orange-red glow when in the"
    locate (21, 27)
    put "tube.   If  air  or the  gas is  almost completely"
    locate (23, 50)
    color (2)
    put "-2-"
end thom_page_2

%  This procedure contains the information for the third page of information
%  dealing with the 'Thomson's Model' option.
procedure thom_page_3
    openpage
    color (2)
    locate (9, 37)
    put "   THE DISCHARGE TUBE con't"
    color (3)
    locate (11, 27)
    put "pumped out,  then the glow nearly disappears,  but"
    locate (12, 27)
    put "the current  continues to  flow.  Scientists found"
    locate (13, 27)
    put "that the current  consists  of invisible rays that"
    locate (14, 27)
    put "originate at the cathode  and travel to the anode."
    locate (15, 27)
    put "These rays are called cathode rays. Thomson worked"
    locate (16, 27)
    put "with these rays and was able to determine that the"
    locate (17, 27)
    put "rays consisted of negatively charged particles.   "
    locate (23, 50)
    color (2)
    put "-3-"
end thom_page_3

%  This procedure contains the information for the fourth page of information
%  dealing with the 'Thomson's Model' option.
procedure thom_page_4
    openpage
    color (2)
    locate (9, 39)
    put "DISCOVERY OF THE ELECTRON"
    color (3)
    locate (11, 27)
    put "   In 1897, Thomson  discovered the electron, then"
    locate (12, 27)
    put "called corpuscles.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                