  The article contains several observations on spherical harmonics and their
nodal sets: a construction for harmonics with prescribed zeroes; a kind of
canonical representation of this type for harmonics on $\bbS^2$; upper and
lower bounds for nodal length and inner radius (the upper bounds are sharp);
precise upper bound for the number of common zeroes of two spherical harmonics
on $\bbS^2$; the mean Hausdorff measure on the intersection of $k$ nodal sets
for harmonics of different degrees on $\bbS^m$, where $k\leq m$ (in particular,
the mean number of common zeroes of $m$ harmonics).
