Sorry, text formatting (ironically) in the web app does not clearly illustrate the problem. See image below

thanks

So reading in the enclosed files and trying the join on the lists resulted in an error

file1List = ReadList[ "first.txt", Number]; file2List = ReadList[ "second.txt", Number];

Join[file1List , file2List , 2]; Resulted in

Expression {1836 -12,1012 -2661,-156 -2916,967 232,1224 1637,-1030 -754,-2002 -2651,-667 -1822,-267 -561,-[Ellipsis] 33,[Ellipsis] ,1292 1055,584 -469,584 -1311,1150 -974,-309 -767,-1949 -212,-719 1262,838 1754,-21 405} at position 1 is expected to have nonatomic subexpression at level 2. >>

Well, yes, according to you second posting I was assuming that your data are already in form of a matrix like so:

{{613, -112}, {1737, 
   392}, {1685, -176}, {1443, -813}, {891, -39}, {273, 1761}, {356, 
   2007}, {-8, -198}, {-882, -1634}} // TableForm

(*output: 613   -112
1737    392
1685    -176
1443    -813
891 -39
273 1761
356 2007
-8  -198
-882    -1634*)

Obviously this is not the case in your example ...

A direct (but not very elegant) way could be:

ClearAll["Global`*"]
SetDirectory[NotebookDirectory[]];
input1 = Import["first.txt", "Data"];
input2 = Import["second.txt", "Data"];
result = Join[input1, input2, 2];
Export["result.txt", 
  StringReplace[
   ToString[result], {"}, {" -> "\n", ", " -> "\t", "{{" -> "", 
    "}}" -> ""}]];

But I have to confess that this is not solving your primary question: This way the entire input files have to be red in first.

Henrik

sorry, missed the export to a file........thanks for your help