At the end of the 19th century, Irish astronomers Johnstone Stoney and A.M.W. Downing showed in principle how to predict meteor storms. Their work and later developments applying similar ideas are reviewed here. The theories essentially involve determining the dynamical behavior of dust trails, which are narrow, dense structures within a broader stream. ... Some Leonid dust trails are perturbed by the planets so as to result in meteor storms at the start of the 21st century. ...

... Fortran . ... The final example shows the program in the new programming language F. program tpk(input,output); (* Pascal program for Unix *) var i : integer; y : real; a : array [0..10] of real; function f (t : real) : real; begin f := sqrt(abs(t)) + 5*t*t*t end; begin for i := 0 to 10 do read(a[i]); for i := 10 downto 0 do begin y := f(a[i]); if y > 400 then writeln(i,' TOO LARGE') else writeln(i,y); end end. ... C THE TPK ALGORITHM C FORTRAN IV STYLE DIMENSION A(11) FUN(T) = SQRT(ABS(T)) + 5.) ...