Translation for this site. The original was Mommsen*:
Aliud miraculum est Duo Rig Habren, id est duo reges Sabrinae. quando inundantur mare ad sissam in
ostium Sabrinae, duo cumuli spumarum congregantur separatim et bellum faciunt inter
se in modum arietum et procedit unusquisque ad alterum et collidunt se ad invicem et iterum secedit alter
ab altero et iterum procedunt in unaquaque sissa. hoc faciunt ab initio mundi usque in hodiernum diem.
Here Sissam is assumed Scissam: See Note on Wonder 2. Morris* translates it as tide, i.e. "When the sea floods into the Severn estuary...they go forth together again at each tide" which is certainly smoother. He also gives Duorig Habren as Dan Ri Hafren.
Here Arietum is from Aries: "Ram", however Lewis and Short* give references to examples in which Aries was also used for an as-yet unidentified sea creature which presumably "rammed" boats; thus "sea-rams", which seems to hedge bets and give a suitable translation.
Färber & Irwin* have "The fifth wonder, i. e. two bubbles of froth at the mouth of the Sabrain. They encounter and break each other, and move back again, and come in collision, again, and thus continue perpetually...[end]"