Bavin (wood) was a traditional unit of firewood, a large log.
A bavin in the 16thC was a piece of wood standardised as three foot long and two feet round. In Hampshire in the early19thC, its cost was between 6 and 15 shillings per hundred bavins.
Charles Vancouver in 1813 wrote of "Bavins for heating the oven and making a sudden but transient fire". Bavins were used especially by bakers.
Jane Austen in 1814 complained to her sister that âÂÂMy MotherâÂÂs Wood is brought in-but by some mistake, no Bavins. She must therefore buy someâÂÂ.