Recently, in reply to a correspondent, it was stated that no spark arrestors on railroad engines had been successful. If the sparks were arrested the draft was destroyed. A recent Boston paper, referring to the paragraph in the Gardener's Monthly, says that there is now an invention which promises absolute success. The Old Colony Railroad Company is putting it on all their new locomotives, and on all the old ones as they come to the shop. The arrangement costs $250 for each appliance, but it will be cheaper than forest fires.