Here the teacher is using one of the direct methods for teaching Latin and Greek advocated by the pioneering schoolmaster and classical scholar William Henry Denham (W.H.D.) Rouse(1863-1950).
Rouse was instrumental in the establishment of the Association for the Reform of Latin Teaching (ARLT) in 1913.
One of his techniques was to set Latin verse to well-known children's song tunes. He believed that this promoted pupils' understanding of linguistic rhythms and developed their vocabulary.
For the verse quoted above, Rouse suggested the tune Jiggety Jog to Market.
Rouse also suggested singing the following lines to the tune of 'Oh My Darling Clementine':
Ecce Caesar nunc triumphat qui subegit Gallias
ecce turbam nunc reducit quae refert victoriam.
hunc Strabonem nominamus clarum ocellis paetulis
dexter ad septentriones, laevus austrum prospicit.