diff --git a/demos/sphere-stl.geo b/demos/sphere-stl.geo
new file mode 100644
index 0000000000000000000000000000000000000000..a93e14885047efe199a035f5b59c7be3da3f6f83
--- /dev/null
+++ b/demos/sphere-stl.geo
@@ -0,0 +1,9 @@
+
+// include an STL triangulation as the representation of the surface 1
+
+Merge "sphere-surf.stl";
+
+// define a volume using that surface
+
+Surface Loop(2) = {1};
+Volume(3) = {2};
diff --git a/examples/cube.geo b/examples/cube.geo
deleted file mode 100644
index decdd4a696bb42dae6ae5bda42e91f3bb5b099e1..0000000000000000000000000000000000000000
--- a/examples/cube.geo
+++ /dev/null
@@ -1,83 +0,0 @@
-lcar1 = .0275;
-
-length = 0.25;
-height = 1.0;
-depth = 0.25;
-
-Point(newp) = {length/2,height/2,depth,lcar1}; /* Point      1 */
-Point(newp) = {length/2,height/2,0,lcar1}; /* Point      2 */
-Point(newp) = {-length/2,height/2,depth,lcar1}; /* Point      3 */
-Point(newp) = {-length/2,-height/2,depth,lcar1}; /* Point      4 */
-Point(newp) = {length/2,-height/2,depth,lcar1}; /* Point      5 */
-Point(newp) = {length/2,-height/2,0,lcar1}; /* Point      6 */
-Point(newp) = {-length/2,height/2,0,lcar1}; /* Point      7 */
-Point(newp) = {-length/2,-height/2,0,lcar1}; /* Point      8 */
-Line(1) = {3,1};
-Line(2) = {3,7};
-Line(3) = {7,2};
-Line(4) = {2,1};
-Line(5) = {1,5};
-Line(6) = {5,4};
-Line(7) = {4,8};
-Line(8) = {8,6};
-Line(9) = {6,5};
-Line(10) = {6,2};
-Line(11) = {3,4};
-Line(12) = {8,7};
-Line Loop(13) = {-6,-5,-1,11};
-Plane Surface(14) = {13};
-Line Loop(15) = {4,5,-9,10};
-Plane Surface(16) = {15};
-Line Loop(17) = {-3,-12,8,10};
-Plane Surface(18) = {17};
-Line Loop(19) = {7,12,-2,11};
-Plane Surface(20) = {19};
-Line Loop(21) = {-4,-3,-2,1};
-Plane Surface(22) = {21};
-Line Loop(23) = {8,9,6,7};
-Plane Surface(24) = {23};
-
-Surface Loop(25) = {14,24,-18,22,16,-20};
-Complex Volume(26) = {25};
-
-n = 21;
-
-/*
-sizex = 4;
-sizey = 6;
-sizez = 4;
-*/
-sizex = n*length;
-sizey = n*height;
-sizez = n*depth;
-
-sizex = 9;
-sizey = 33;
-sizez = 9;
-
-
-Transfinite Line {2,4,9,7} = sizez;
-Transfinite Line {11,5,10,12} = sizey;
-Transfinite Line {3,1,6,8} = sizex;
-
-Transfinite Surface {14} = {5,4,3,1};
-Transfinite Surface {16} = {6,2,1,5};
-Transfinite Surface {18} = {6,2,7,8};
-Transfinite Surface {20} = {3,7,8,4};
-Transfinite Surface {22} = {3,7,2,1};
-Transfinite Surface {24} = {4,8,6,5};
-
-Recombine Surface {14,16,18,20,22,24};
-
-Transfinite Volume {26} = {3,7,2,1,4,8,6,5};
-
-Physical Surface(200) = {14,16,18,20,24};
-
-Physical Volume(100) = {26};
-/*
-Mesh.use_cut_plane = 1;
-Mesh.cut_planea = 0;
-Mesh.cut_planeb = 0;
-Mesh.cut_planec = 1;
-Mesh.cut_planed = -0.125;
-*/
\ No newline at end of file