[Footnote 157: "Many of these mountains are very high. During my stay in Canada, I asked many people who have traveled much in North America whether they ever met with mountains so high that the snow never melts on them in summer, to which they always answered in the negative. They say that the snow sometimes stays on the highest, viz., on some of those between Canada and the English colonies during a part of the summer, but that it melts as soon as the great heat begins."--Kalm, p. 671.] [Footnote 158: "It is worthy of remark, and not a little surprising, that so large a river as the St. Lawrence, in latitude 47 deg., should be shut up with ice as soon, and continue as long shut up, as the comparatively small river, the Neva, in latitude 60 deg.."--Gray's _Canada_, p. 320.] [Footnote 159: "The following curious experiments were made some years ago at Quebec, by Major Williams, of the Artillery. Iron shells of different sizes, from the thirteen-inch shell to the cohorn of four inches diameter, were nearly filled with water, and an iron plug was driven in at the fuse-hole by a sledge-hammer. It was found, however, that the plug could never be driven so firmly into the fuse-hole as to resist the expanding ice, which pushed it out with great force and velocity, and a bolt or cylinder of ice immediately shot up from the hole; but when a plug was used that had springs which would expand and lay hold of the inside of the cavity, so that it could not possibly be pushed out, the force of expansion split the shell. The amazing force of expansion is also shown from the distance to which these iron plugs are thrown out of the fuse-hole. A plug of two pounds and a half weight was thrown no less than 415 feet from the shell; the fuse axis was at an angle of 45 deg.; the thermometer showed 51 deg. below the freezing point. Here you see ice and gunpowder performing the same operations. That similar effects should proceed from such dissimilar causes is very extraordinary."--Gray's _Canada_, p. 309.] [Footnote 160: See Appendix, No. XXII. (see Vol II)] [Footnote 161: "These mountains were known to the French missionaries by the name of Montagnes des Pierres Brillantes."--Chateaubriand.] [Footnote 162: See Appendix, No. XXIII. (see Vol II)] [Footnote 163: See Appendix, No. XXIV. (see Vol II)] [Footnote 164: See Appendix, No. XXV. (see Vol II)]