  We analyze the temporal variations of the sizes and emission intensities of
thirtyone flaring kernels in various parts of the H{\alpha} line profile. We
have found that the areas of all kernels decrease systematically when observed
in consecutive wavelengths toward the wings of the H{\alpha} line, but their
areas and emission intensity vary in time. Our results are in agreement with
the commonly accepted model of the glass-shaped lower parts of the magnetic
flaring loops channelling high energy variable particle beams toward the
chromospheric plasma. High time resolution spectral-imaging data used in our
work were collected using the Large Coronagraph and Horizontal Telescope
equipped with the Multi-channel Subtractive Double Pass Spectrograph and the
Solar Eclipse Coronal Imaging System (MSDP-SECIS) at the Bia{\l}k\'ow
Observatory of the University of Wroc{\l}aw, Poland.
