It is objected, however, by Professor Kirkwood that even if we admit that the solar system originated in the collision, 800 millions of years ago, of two cold opaque bodies approaching each other in the same straight line, with a velocity of 1,700 miles per second, we must consider that only a portion of this period is represented by geological time. For after the collision ages must have elapsed before the planets had separated from the parent mass, and had sufficiently cooled down to commence their geological history. When, however, the heated planet had cooled down to a temperature low enough to admit of the formation of an outer crust, its development into a life-bearing world would then be comparatively rapid. For Sir William Thomson has shown that the internal heat would have no appreciable effect upon the temperature of the earth's surface 10,000 years after the formation of a definite crust. This follows from the fact that the heat-conducting power of the igneous rocks is very small. An illustration of this may be observed in lava recently ejected from a volcano, which may be walked over without danger, while a few feet below its surface it still remains in the molten state. Trowbridge has shown that, were the temperature of the sun's surface "twice its present intensity, the solar atmosphere would be expanded beyond the earth's orbit." Under these conditions all forms of life would, of course, be impossible on the surface of our globe. therefore, Trowbridge's result be correct, it would follow that the shrinkage of the sun's mass from the diameter of the earth's orbit to its present size must have taken many millions of years.

If,

Professor Kirkwood is disposed to believe it more probable "that in former ages the stratification of the earth's crust proceeded more rapidly than at present." Geologists of the uniformitarian school do not, however, seem willing to admit this hypothesis as probable, and a short account of the evidence adduced by Dr. Croll as to the probable duration of geological time-a subject on which he was a well-known authority-may prove of interest to those of my readers who, like myself, take an interest in geological science.

Dr. Croll considers that any attempt "to compress the geological history of our globe into the narrow space allotted by the physicist is hopeless, as well as injurious to geological science." He proceeds to obtain "an accurate measure of absolute geological time" by a consideration of the results of sub-aërial denudation, and the method he adopts to ascertain the amount of this denudation is by an estimate of the quantity of sediment annually carried down to the sea by the great river systems. From a number of rivers on which experiments in this direction have been made, he selects the Mississippi as draining a country "which may be regarded as in every way resembling the average condition of the earth's surface"; and from experiments made by Messrs. Humphreys and Abbott on the amount of sediment annually carried down to the sea by this river, he arrives at the conclusion that one foot in 6,000 years may "be safely taken as the average rate of denudation of the whole surface of the globe." As, however, the area of the water surface is three times that of the land, this amount would be equivalent to a layer, three inches thick, spread over the whole globe.

Assuming then, that the average rate of denudation in past geological ages did not materially differ from what it is at present, and that the total quantity of stratified rock would, if uniformly spread over the whole globe, form a layer 1,000 feet in thickness, we have a total period of 1,000 multiplied by 6,000 multiplied by four, or 24 millions of years. This, however, only represents the time necessary to deposit the rocks which have been formed by denudation from older rocks, and these again from rocks of still greater antiquity. Assuming that the existing stratified rocks have thus passed three times through denudation and deposition, we have a period of 72 million years.

Dr. Haughton, calculating from the observed thickness of the rocks down to the Miocene Tertiary, and assuming a period of 8616 years for each foot deposited on the ocean bed, finds, for the age of the stratified rocks, a period of 1,526,750,000 years! Assuming the rate of denudation, however, as ten times greater in ancient times than at present, and adding one-third for the period since the Miocene Tertiary, he arrives at a final result of 200 millions of years! Dr. Croll doubts the validity of Professor Haughton's assumptions, especially the total thickness he assumes, namely, 177,200 feet, or over 33 miles.

Mr. A. R. Wallace, adopting Dr. Haughton's thickness, but assuming the sediment to be deposited along a belt of 30 miles wide round the whole coast-line of the globe, finds, with an assumed denudation of one foot in 3,000 years, a period of 28 million years. This, however, on Dr. Croll's assumption of re-formation and denudation repeated several times, would be merely a fraction of the time required.

Dr. Croll further shows from the evidence of remarkable "faults" in various parts of the world, with "downthrows" ranging from 3,000 to 20,000 feet, the enormous amount of solid rock which must have been denuded off the surface of the earth during the progress of geological history. He estimates that three miles of rock have been removed since the beginning of the Old Red Sandstone. This would indicate a period of forty-five millions of years. Assuming that the period before the Old Red Sandstone was equally long, we have 90 millions of years as the "minimum duration of geological time."

These enormous periods of time do not, however, seem to satisfy the demands of the biologists and the supporters of the Darwinian theory. Judging "from the fact that almost the whole of the Tertiary period has been required to convert the ancestral Orohippus into the true horse," Professor Huxley believes "that in order to have time for the much greater change of the ancestral ungulata into the two great odd-toed and even-toed divisions (of which change there is no trace even among the earliest Eocene mammals) we should require a larger portion, if not the whole, of the Mesozoic or Secondary period," and still longer periods are demanded for the evolution of other animals, "so that, on the lowest estimate, we must place the origin of the mammalia very far back in Palæozoic times." Mr. Wallace speaks of possible periods of 200 and even 500 millions of years! To account for the existence of the solar heat during these vast æons of time, it would be necessary to increase Dr. Croll's original assumption of a velocity of 476 miles per second very considerably. Astronomers do not, of course, deny the mathematical accuracy of Dr. Croll's conclusions, but they consider that such enormous velocities are highly improbable, and the collisions themselves equally so. Without the aid of such collisions physicists will not admit that the sun's life history can be extended backwards beyond a limited number of millions of years. The evidence afforded by geology seems to require a much longer period. Biologists and evolutionists demand still more, and hence has arisen a scientific conflict, which at present-unless we accept Dr. Croll's hypothesisthere seems to be no hope of bringing to a satisfactory conclusion.

J. ELLARD GORE.

T

THE INNS OF COURT.

HE Norman Conquest brought to this country a swarm of adventurers, amongst whom the most notable were lawyers, from the other side of the English Channel. These were for the most part Norman clergy and members of religious confraternities, whose numbers comprised the best educated men of the time, or, at any rate, the men who had the greatest opportunities of improving their minds in all matters of science and learning. The English laity must have regarded these new-comers, of foreign language, foreign manners, and foreign customs, with the same mixture of wonder and contempt as did the rustics the voluble Cheap Jack at the country fair-beings, in fact, whom they could not understand, but who they felt certain were trying to outwit them. In course of time these alien clerics elbowed their way into all the best posts in the English monasteries, universities, and courts of justice, and used their very best endeavours to crush out of existence the common law of England-that ancient collection of unwritten traditions and customs which none but a native could appreciate, and for which they naturally had no sympathy and strove to introduce in its place the civil code of the old Roman Empire, and its offspring, the canon law of the Catholic Church. This was the beginning of a long struggle between the promoters of the two systems of jurisprudence. On one side was ranged the powerfully organised body of ecclesiastics, on the other the laity, nobles and commons, and a sprinkling of Churchmen.

In the reign of Henry III., however, the clergy were forbidden by authority of the Church to act as advocates in the secular courts, unless as representing their own private interests or those of the destitute. Very unwillingly, we may be sure, the clerics retired from a practice that had gotten them much gain, and not a few whose consciences were sufficiently elastic took advantage of the obvious loophole of escape from the ecclesiastical prohibition, and continued to appear to plead the cause of "the destitute" in foro sæculari. To cut a long story short, the tonsured practitioner gradually became a rara avis, and at last as extinct as the dinornis and the dodo. A statute passed in the thirty-sixth year of Edward III. enacted that all pleas in the courts of the King should be pleaded and judged in the English tongue instead of the French, a knowledge of which had hitherto been indispensable to the professional pleader. The removal of this restriction must have attracted an increased number of students to the legal profession.

In the meantime the lay practitioners, who were thus left in sole possession of the field, had formed themselves into associations, resembling in some respects the guilds of merchants and traders formerly so numerous in this country, with a view to protecting their own interests, and excluding from the practice of the law all who had not served a term of probation, and thereby become initiated into the mysteries and art of the profession. Thus we find the students of law referred to in the old books as apprentices (apprenticii ad legem). Apprentices they were, in truth, for in those days a long and steep road had to be climbed by the aspirant to legal honours, and many weary years had to be passed by him in the study of the law before he could appear as an advocate in the courts. The period of probation seems at first sight to be one of inordinate length, but it must be remembered that the attainment of a knowledge of the common law was then a very different matter from what it is nowadays, when a multitude of judicial decisions and learned text-books have rendered the study of the old lex non scripta a comparatively easy one. Besides, the student could not then, as he can now, obtain a preliminary insight into its principles at the universities, for its study was discouraged in those seats of learning while they remained under the influence of the clerical professors of the civil law.

It would seem that all members of the associations we have mentioned were sometimes comprised in the general term "apprentice," and it was not until the lawyer had attained the high dignity of serjeant-at-law (serviens ad legem), that he dropped the former appellation. We accordingly find in Richard II.'s reign a reference to three grades of apprentices-greater apprentices, apprentices who practised the law, and apprentices of less estate-who are classed with, and probably were often in fact, attorneys-at-law.

In order that the reader's mind may not become confused by these conflicting meanings of the word "apprentice," it must be stated that in these pages it is generally used as applicable only to the junior members of the Societies in question.

About the time of Edward III., it has been conjectured, the