Professor Halir would teach double-stops and scales in thirds in a free, broad style, lower half of the bow (note fingering in the second position).
The whole bow may also be used. Play the scale runs, second line, in the manner outlined in Halir’s Tonleiterstudien (G.B. or U.H. raise the bow after each group).
He assumes that short position movements make a more perfect scale in thirds possible. I will outline the bowings for the next three lines. Keep the theme prominent. Raise the bow slightly from the strings in defining phrasing.
The double-stops in the higher positions naturally fall in the middle of the bow. Attack the chords with the up bow firmly, and play three notes together. A free, rather detached bowing in the middle of the bow, using the artificial spiccato, occurs at the close.