Section 42. No person engaged in the business of displaying or exhibiting fireworks shall, by himself or his agents, discharge, fire off, explode or display fireworks unless he has on file with the state treasurer a bond running to the state treasurer with a surety or sureties approved by him for the penal sum of fifteen thousand dollars, and for such additional penal sum as the marshal shall determine to be necessary to cover the losses, damages or injuries that might ensue to persons or property by reason thereof. The bond shall be conditioned upon the payment of any judgment obtained in an action brought against said person so discharging, firing off, exploding or displaying fireworks, for or on account of any loss, damage or injury resulting to persons or property by reason of the said discharging, firing off, exploding or displaying of said fireworks. As used in this section, the word ''persons'' shall include municipal corporations, and the word ''loss'' shall include the reasonable expense of a city or town incurred in the extinguishing of fires caused by said discharging, firing off, exploding or displaying of said fireworks.