A critical edition of all the previously known fables, prepared by Carl von Halm from the collections of Furia, Coray and Schneider, was published in the Teubner series of Greek and Latin texts.
Halm deduced a velocity of 20.8 km.
Halm subsequently showed that if N may differ in different cases, the equation is a considerable improvement on Rydberg's.
Halm,' to whom we owe a careful comparison of the above equation with the observed frequencies in a great number of spectra, attached perhaps too much weight to the fact that it is capable of representing both line and band spectra.
His commentary on Cicero's De Inventione (in Halm's Rhetores Latini Minores, 1863) is very diffuse, and is itself in need of commentary.
If r =1, we obtain Pickering's equation, which is the one advocated by Halm.
Jahn (1852), C. Halm (1854), which contain the fragments of the Virgilian dialogue.