diff --git a/demos/sphere.geo b/demos/sphere.geo
index b8654b81b28c343eeb780cf41cb9e22577e0d2b6..ca63d179db28b2634752f8361e1bf8afdc6a1ea5 100644
--- a/demos/sphere.geo
+++ b/demos/sphere.geo
@@ -1,4 +1,6 @@
-lc = .2;
+Mesh.Algorithm = 6;
+
+lc = .55;
 Point(1) = {0.0,0.0,0.0,lc};
 Point(2) = {1,0.0,0.0,lc};
 Point(3) = {0,1,0.0,lc};
@@ -37,5 +39,5 @@ Ruled Surface(28) = {27};
 Surface Loop(29) = {28,26,16,14,20,24,22,18};
 Volume(30) = {29};
 
-// try also netgen:
-// Mesh.Algorithm3D = 4;
+Physical Surface(1) = {28,26,16,14,20,24,22,18};
+Physical Volume(2) = 30;
diff --git a/doc/texinfo/gmsh.texi b/doc/texinfo/gmsh.texi
index 64cf3b4ce5e9a6df65d6657cff2b7b98602b1e82..9bbf53e6f6db2da01eea67cd36642b1124b778d1 100644
--- a/doc/texinfo/gmsh.texi
+++ b/doc/texinfo/gmsh.texi
@@ -3257,7 +3257,7 @@ map instead of a vector to access nodes and elements. The performance
 hit is on speed. For post-processing datasets, which always use vectors
 to access data, the performance hit is on memory. A @code{NodeData} with
 two nodes, tagged 1 and 1000000, will allocate a (mostly empty) vector
-of 1000001 elements.
+of 1000000 elements.
 
 Any section with an unrecognized header is simply ignored: you can thus
 add comments in a @file{.msh} file by putting them e.g. inside a