  We consider the dynamics of and emission from growing superbubbles in a
stratified interstellar gaseous disc driven by energy release from supernovae
explosions in stellar clusters with {masses $M_{cl}= 10^5-1.6\times
10^6~M_\odot$}. Supernovae are spread randomly within a sphere of $r_c=60$ pc,
and inject energy episodically with a specific rate $1/130~M_\odot^{-1}$
proportional to the star formation rate (SFR) in the cluster. Models are run
for several values of SFR in the range $0.01$ to $0.1~M_\odot$ yr$^{-1}$, with
the corresponding average surface energy input rate $\sim 0.04-0.4$ erg
cm$^{-2}$ s$^{-1}$. We find that the discrete energy injection by isolated SNe
are more efficient in blowing superbubbles: asymptotically they reach heights
of up to 3 to 16 kpc for $M_{cl}=10^5-1.6\times 10^5~M_\odot$, correspondingly,
and stay filled with a hot and dilute plasma for at least 30 Myr. During this
time they emit X-ray, H$\alpha$ and dust infrared emission. X-ray liminosities
$L_X\propto {\rm SFR}^{3/5}$ that we derive here are consistent with
observations in star-forming galaxies. Even though dust particles of small
sizes $a\leq 0.03~\mu$m are sputtered in the interior of bubbles, larger grains
still contribute considerably ensuring the bubble luminosity $L_{\rm IR}/{\rm
SFR}\sim 5\times 10^7 L_\odot M_\odot^{-1} ~{\rm yr}$. It is shown that the
origin of the North Polar Spur in the Milky Way can be connected with activity
of a cluster with the stellar mass of $\sim 10^5~M_\odot$ and the ${\rm
SFR}\sim 0.1~M_\odot$ yr$^{-1}$ some 25--30 Myr ago. Extended luminous haloes
observed in edge-on galaxies (NGC 891 as an example) can be maintained by disc
spread stellar clusters of smaller masses $M_\ast \simlt 10^5~M_\odot$.
