FOOTNOTES:
[1] Tennyson, "In Memoriam," cvi.
[2] Homer, "Odyssey," v. 273.
[3] Homer, "Odyssey," Book v., 121-124.
[4] Ibid., Book xi., 571-574.
[5] The pole-star, however, is not the true polar point, but distant from it about 1° 32', which, in A.D. 2100, will be decreased to 26' 30".
[6] Homer, "Odyssey," Book v., 275.
[7] Manilius, "Astronomicon," Book i., 291-300.
[8] Manilius, "Astronomicon," i., 308, 309.
[9] This displacement amounts to about fifty seconds annually, or, more accurately, to 50".3. It is easy, therefore, to calculate that the complete rotation of the terrestrial axis around the poles of the ecliptic will occupy 25,765 years.
[10] These are also called the Pointers, because an imaginary line from the lower to the upper, prolonged in the same direction, passes nearly over the Polar Star.
[11] Pliny, "Historia Naturalis," Book ii., 24.
[12] Chaplin Child, "Beredici," p. 171.
[13] Pliny, "Historia Naturalis," Book xi.
[14] De Saussure, "Voyage dans les Alpes," Book iii., p. 45 (ed. 1803, Neufchâtel).
[15] Annales de Chimie et de Physique, vol. xxvii., p. 134.
[16] Philosophical Transactions, 1820, vol. ii., p. 165.
[17] It is but fair to add, however, that Vogt and others contend for the animal origin of this substance, and regard the Protococcus nivalis as simply a development of the infusoria, Disceræa nivalis.
[18] Macmillan, "Footnotes from the Page of Nature," pp. 141-143.
[19] The two temperate zones together represent perceptibly the half, or 0.520, and the torrid zone, two-fifths, or, more exactly, 0.398, of the terrestrial surface.
[20] That is, muttering, marmot-wise, one's prayers.
[21] Byron.
[22] Also called the Golden-crested Wren.
[23] C. Vogt, Agassiz, und seiner Freunde geologische Alpenreisen, p. 181. Frankfort, 1847.
[24] A flower with a stalk is called pedunculate or pedicellate; without a stalk, it is sessile.
[25] Pliny, "Historia Naturalis," xxv. 18.
[26] Dioscorides, "Materia Medica," iv. 191.
[27] Tragus, "Historia Stirpium" (ed. 1552).
[28] Tournefort, "Histoire des Plantes" (ed. 1727), i. 74, 75.
[29] Turnsole, a colouring substance made of coarse linen rags, which, after being cleaned and bleached, are dipped into a mixture of ammoniacal matter, and the juice of the Crozophora tinctoria.
[30] Leaves are said to be linear, when the veins do not spread out, but run from the base to the extreme point.
[31] A stigma is the continuation of the cellular tissue of the style, and has sometimes projecting cellules of hairs.
[32] A whorl, or ring, of bracts (floral leaves) is so called.
[33] Diodorus, i. 43.
[34] Pliny, "Historia Naturalis," xxiv. 188.
[35] Dioscorides, iv. 30.
[36] Theophrastus, "Historia Plantarum," i. 10; xi. 2, 4.
[37] Tournefort, "Histoire des Plantes," ii. 54.
[38] Seneca, "Quæstiones Naturales," vi. 6.
[39] Lactantius, "De Falsa Sapientia," iii. 24.
[40] The best means of ascertaining the coexistence of an ascending and descending sap have been indicated in "The Circle of the Year," pp. 163-8.
[41] See the Botanische Zeitung ("Botanical Gazette") for the years 1853, 1856, 1859, and 1861.
[42] Boehm, "Sur la Cause de l'Ascension de la Séve," Mémoire communiqué à l'Académie des Sciences de Vienne, juillet 1863.
[43] Chaucer.
[44] Pliny, "Historia Naturalis," xxvi. 5.
[45] See "The Circle of the Year."
[46] Chomel, "Histoire des Plantes Usuelles," ii. 282.
[47] Tournefort, "Histoire des Plantes," i. 103.
[48] Garidel, "Histoire des plantes qui naissent aux environs d'Aix," p. 56.
[49] "Pied," that is, vari-coloured, motley-coated.
[50] See also Shelley's "Sensitive Plant," &c.
[51] This is common enough in Germany and France, especially in the vineyards, but very rare in England.
[52] So we say, "fretted roof."
[53] When the spike bears numerous flowers, surrounded by a spathe, or sheathing bract, it is called a spadix.
[54] Bosc, a distinguished naturalist, died in 1828, aged 69. In the ministry of Roland, he accepted the delicate post of administrator of prisons; was proscribed after the terrible events of May 31, 1793; and lay concealed, along with Laréveillière-Lépaux, for several weeks in the forest of Montmorency.
[55] The seeds of the latter are used in the East, where they are more pungent than in our cold climates, instead of pepper. "They are thought to be the cummin alluded to in Scripture, where our Saviour reproved the Pharisees for their singularity in minor things, and their neglect of important duties."
[56] That is, the Creative Power which, in common parlance, we choose to call Nature.
[57] No one, I think, has ever before attempted to reconcile, in this way, the two principal theories which have been put forth on the propagation of light.
[58] "The term perianth is usually confined to the flowers of Endogens, whatever colours they present, whether green, as in asparagus, or coloured, as in tulip. Some use the term as a general one, and restrict the use of perigone to cases where a pistil is present, not applying it to unisexual flowers, in which stamens only are produced."—Professor Balfour, "Manual of Botany," p. 169.
[59] Homer, "Odyssey," Book xix., line 520.
[60] Grew, "Anatomy of Plants," p. 147.
[61] Barry Cornwall.
[62] Tragus, "Historia Stirpium," p. 310 (ed. 1552).
[63] Fabius Columna (Fabio Colonna), an Italian man of science, who died in 1650, at the age of eighty-three.
[64] Thomas Campbell.
[65] Anne Pratt, "Flowers and their Associations" (ed. 1846).
[66] Draba aretoides has been found on Chimborazo at 16,000 feet.
[67] Poa annua grows at an elevation of 7400 feet.
[68] Aristotle, "Hist. Animal.," i. 9.
[69] Pliny, "Hist. Nat.," xi. 52.
[70] Pliny, "Hist. Nat.," xxx. 7, 12, 24.
[71] Pliny, "Hist. Nat.," xi. 36.
[72] Newman, "Introduction to the History of British Insects."
[73] Ptolemæus, "Syntaxis Mathematicalis," iii. 3.
[74] Certain astronomical calculations, so called because begun under the patronage of Rudolf II., Emperor of Germany (1576-1612).
[75] Kepler, "Astronomia Nova, seu de Motibus Stellæ Martis," p. 53 (ed. 1609).
[76] The reader should turn to Kepler's immortal work, "De Motibus Stellæ Martis," for the manifold attempts of the astronomer to bring calculation into agreement with observation. In every page is revealed what has been finely called "the passionate patience of genius."
[77] There is certainly no exaggeration in comparing the earth to a point, since the diameter of the sun is 112 times that of the earth, and its mean distance a little more than 12,000 terrestrial diameters: the earth is but a microscopical point in space, if we compare it to the place occupied by the central luminary.
[78] Reference is here invited to Humboldt's thermal and isothermal lines. See Dr A. K. Johnston's "Physical Atlas," and Humboldt's "Kosmos."
[79] Sir J. Herschel, "Preliminary Discourse on the Study of Natural Philosophy."
[80] Professor Balfour's "Manual of Botany," pp. 566-568.
[81] Pliny, "Hist. Nat.," xxii. 46.
[82] Martial, "Epigram.," i. 21.
[83] "Annales des Sciences Naturelles," i. 18.
[84] Count de Castelnau, "Histoire Naturelle des Coléoptères," i. 7.
[85] As recorded, in a condensed form, in The Academy (Feb. 12, 1870), pp. 131, 132.
[86] This section is translated from M. Hoefer, without addition or alteration.
[87] From these slow movements, which have been designated the "secular inequalities," we might with some probability infer the end of the world, which even Newton regarded as certain,—at least, unless "the Great Architect at times retouched His work." The inequalities or secular variations affect the elements of the orbits, such as the inclination of the plane of the orbit,—the semi-major axis of the ellipse, or the mean distance of the planet from the sun,—the eccentricity of the ellipse, or the relation between the distance which separates the forces from the centre and the semi-major axis assumed to be unity,—and the movements of the perihelions and the nodes. These elements change with extreme slowness. Thus, the inclination of Jupiter diminishes by 8" in a century; and that of Saturn increases by 9"; but the very ecliptic varies,—it diminishes 33" in a century.
The variations of the eccentricities are scarcely computable by centuries; their effect is, that the ellipses insensibly approach or recede from a circular form.
It is demonstrated by mathematical analysis that these variations are periodical, and confined within narrow limits, in such wise that "the planetary system can oscillate only round a certain mean, from which it never departs except by a very small quantity." But may not this very mean, which we have taken to be constant, oscillate round a more distant and still more constant mean?
Observation had long ago detected a continual acceleration in the movement of Jupiter, and a not less certain diminution in the movement of Saturn. Now, to say of a star that its velocity augments, is to declare that it draws nearer its centre of movement. To say that its velocity decreases, is to affirm that it is retiring from that centre.
It would seem, therefore, that Jupiter,[88] the greatest of our planets, is destined to be swallowed up, or absorbed, in the incandescent mass of the Sun, while Saturn,[89] with its belt and eight satellites, will gradually wander further and further into the mysterious infinity of space. It is true enough that these catastrophes are very distant,—distant to a period of time which the human imagination cannot even grasp,—and the "common herd" will certainly feel no anxious apprehension about an event which will not take place until myriads of years have elapsed.
Yet, in the last century, the question excited the curiosity of certain scientific societies, and they directed the attention of the geometers to these formidable perturbations. Euler and Lagrange spent their keen intellects upon them to no profit. Laplace discovered that between the mean velocities of Jupiter and Saturn the ratios are simple, and capable of calculation; five times the velocity of Saturn perceptibly equals ten times the velocity of Jupiter. These terms, which, in the regularly-decreasing and indefinite series, might have been neglected, have acquired a value which was worthy of being taken into consideration. From thence result, in the movements of the two planets, those perturbations whose complete development necessitates a period of upwards of nine hundred years.... This will be, then, another periodic inequality.
But, independently of the centres, which we suppose to be in themselves variable, may there not exist, in the space traversed by our planet, some cause of perturbation? Is our system so isolated in the universe that it neither receives nor loses aught of that which constitutes its force and matter? Is there no solidarity between its different worlds? And if this solidarity exists, is not their transformation a necessity?
[88] The equatorial diameter of Jupiter in English miles is 56,065; its density is ·24 of the Earth's; its distance from the sun, 494,270,000 miles; inclination of its orbit to the ecliptic, 1° 18' 51".
[89] The equatorial diameter of Saturn in English miles is 79,147; its density, ·12, the Earth = 1; its distance from the sun, 906,200,000 miles; and the inclination of its orbit to the ecliptic, 2° 29' 36".
[90] Our author, it must be understood, is considering these questions apart from the Scriptural standpoint.
[91] William Drummond.
[92] Samuel Rogers.
[93] "Nature," vol. i. p. 543.
[94] Flammarion, "Les Merveilles Celestes," pp. 160, 161.