It is so important that the public ways be kept free for travel, that any person may take down and remove gates, rails, bars, or fences upon or across highways, unless the same have been there placed for the purpose of preventing the spreading of a disease dangerous to the public health, or have been erected or continued by the license of the selectmen or county commissioners.[14] A highway surveyor acting within the scope of his authority may dig up and remove the soil within the limits of the public ways for the purpose of repairing the same, and may carry it from one part of the town to another;[15] and he has a right to deposit the soil thus removed on his own land, if that is the best way of clearing the road of useless material.[16] [14] Pub. St. c. 54. [15] 125 Mass. 216. [16] 128 Mass. 546. Though the law is imperative that the roads must be kept in good condition, and to this end gives municipal corporations great powers, yet let no one who is not a highway surveyor or in his employ imagine that he can repair a road not on his own land with impunity; for it has been decided that if an unauthorized person digs up the soil on the roadside by another person's land for the purpose of repairing the road, he is a trespasser and liable for damages, although he does only what a highway surveyor might properly do.[17] It is also the duty of cities and towns to guard with sufficient and suitable railings every road which passes over a bank, bridge, or along a precipice, excavation, or deep water; and it makes no difference whether these dangerous places are within or without the limits of the road, if they are so imminent to the line of public travel as to expose travellers to unusual hazard.[18] But towns are not obliged to put up railings merely to prevent travellers from straying out of the highway, where there is no unsafe place immediately contiguous to the way.[19] [17] 8 Allen, 473. [18] 13 Allen, 429. [19] 122 Mass. 389. The roads are for the use of travellers, and a city or town is not bound to keep up railings strong enough for idlers to lounge against or children to play upon.[20] [20] 3 Allen, 374; 8 Allen, 237. The travelled parts of all roads ought to be wide enough to allow of the ordinary shyings and frights of horses with safety, for shying is one of the natural habits of the animal;[21] although it seems that switching his tail over the reins is not a natural habit of the animal, as it has been decided that if a horse throws his tail over the reins and thereby a defect in the road is run against, no damages can be recovered.[22] [21] 100 Mass. 49. [22] 98 Mass. 578. CHAPTER VII. GUIDE-POSTS, DRINKING-TROUGHS, AND FOUNTAINS.