Captain Calver, R.N., has by command of the Admiralty surveyed the Thames below Woolwich to ascertain whether the discharge of the sewage of London into the river has created obstructions in the channel. The captain has published his report, and a very discouraging report it is, for it makes known that shoals have formed, and are forming, which in course of time will completely stop the navigation of the river. In this we have a proof that it is a mistake to send the solid portion of sewage into a stream, in the hope that it will be effectually carried away by the tide. It is not carried away; but is deposited at the bends, and in the eddies, with detriment to health as well as to the water-way.
Engineers who contend that none but neutralised liquid sewage should pass into a river are manifestly in the right. To discharge the solids is a waste as well as a mischief; and if it goes on, the whole of the land will some day be utterly starved for want of nitrogen. Some theorists argue that it won’t pay to attempt to convert the solids into a fertilising material. The answer to this is the experience gained at Aylesbury, where the solid part of the town sewage is separated from the liquid by precipitation; is converted into a fertiliser, part of which is used on the town-farm, and the surplus, in the form of a dry, scentless powder, is sold at three pounds ten shillings the ton. A single grain of oats, sown on land treated with this powder, produced seven thousand grains from one root, and other grains yielded varying numbers down to two thousand. The powder on analysis seems poor; but its richness of productive power may be judged of from the foregoing statement.
A new process for making sulphate of soda has been invented by M. Fournier, a Frenchman. It leaves behind as waste liquid a large quantity of a certain chloride, which turns out to be excellent for the precipitation of sewage. Hence it appears that nature and science combine to shew how the fertility of the land and the free channels of rivers may alike be maintained. The process has been patented in this country, and if all go well we may hope, in time, to hear that the sewage of London, instead of filling up the bed of the Thames, is increasing the fruitfulness of fields, gardens, and meadows in Essex and Kent.
Meteorologists, in their review of the weather, inform us that in the gale on the 11th of November last, the barometer was lower, the wind stronger, and the rainfall greater, than on any other day in the year. The mean velocity of the wind was thirty-eight miles an hour; and the rainfall in twenty-four hours amounted to a little more than an inch and a half. The fall for the whole month was in Sussex, eight and a quarter inches; in Cumberland, nine and three-quarter inches; being, as regards the Sussex gauge, more than five inches above the average of the previous ten years. The total rainfall in eleven months, January to November, was thirty-three and one-third inches: a remarkable excess over twenty-eight inches, which is the usual average for the whole year. For those who are curious in comparisons we take a fact from the weather-records of New South Wales: at Newcastle in that colony there fell on March 18, 1871, more than ten and a half inches of rain in two hours and a half.
Two official papers published in India further discuss the question–sun-spots and rainfall. ‘The Cycle of Drought and Famine in Southern India,’ contains a statement of the argument by Dr W. W. Hunter, and the conclusions to which he has arrived. These are: ‘That although no uniform numerical relation can be detected between the relative number of sun-spots and the actual amount of rainfall, yet that the minimum period in the cycle of sun-spots is a period of regularly recurring and strongly marked drought in Southern India–That apart from any solar theory, an examination of the rain registers shews that a period of deficient rainfall recurs in cycles of eleven years at Madras ... that the statistical evidence shews that the cycle of rainfall at Madras has a marked coincidence with a corresponding cycle of sun-spots ... and that the evidence tends also to shew that the average rainfall of the years of minimum rainfall in the said cycle approaches perilously near to the point of deficiency which causes famine.’ The average is, however, above that point; and though droughts and famines may recur in the cyclic years of minimum rainfall, the evidence, in Dr Hunter’s opinion, is insufficient to warrant the prediction of a regularly recurring famine.
The observations on which these conclusions are founded include sixty-four years of the present century: too short a period on which to build a theory; but as no records exist earlier than 1810, it is by future observation only that the conclusions can be tested. Meanwhile meteorological observers will be watchful, especially of the rainfall, for India is a country which affords singularly favourable opportunities for a comprehensive system of observations.
The other paper referred to above is by Mr H. F. Blanford, Meteorological Reporter to the government of India. He points out that Dr Hunter’s views apply exclusively to Southern India, and that in Northern India famines are most frequent at the epochs of most sun-spots. This lack of agreement between two competent authorities shews how great is the need for a lengthened series of observations.
In the recent Arctic Expedition twenty-five species of fossil plants were discovered in Grinnell Land by Captain Feilden. They are of the period described by geologists as Miocene, and can be identified with species of the same period found in Europe, in North-western America, and in Asia. Among them are two kinds of Equisetum, poplar, birch, elm, and pine. It was suggested at a meeting of the Geological Society that the bed of lignite in which these remains were met with was in remote ages a large peat-moss, probably containing a lake in which the water-lilies grew, while on its muddy shores the large reeds and sedges and birches and poplars flourished. The drier spots and neighbouring chains of hills were probably occupied by the pines and firs, associated with elm and hazel. Among all these which indicate a primeval forest, the only sign of animal life discovered was a solitary wing-case of a beetle.
When water-lilies were growing in that now desolate region, fresh-water must have filled the ponds and lakes. Captain Feilden’s discovery may be taken as additional evidence of a change of climate, which the palæontologists and physicists who are now discussing that interesting question will not fail to make use of on fitting occasion.
A few years ago the British Association appointed a committee of eminent mathematicians to consider ‘the possibility of improving the methods of instruction in elementary geometry.’ The Report of this committee was published in the stout volume which contains the account of the meeting held at Glasgow. It states that the main practical difficulty in effecting the improvement is ‘that of reconciling the claims of the teacher to greater freedom with the necessity of one fixed and definite standard for examination purposes;’ that ‘no text-book yet produced is fit to succeed Euclid in the position of authority, and that a syllabus of propositions in a definite sequence to be regarded as a standard sequence for examination purposes, might be published.’ Such a syllabus as is here implied has been brought out by the Association for the improvement of geometrical teaching; and the committee recommend it for adoption by the universities and other great examining bodies of the United Kingdom. ‘It may be well to observe,’ they say in their Report, ‘that the adoption of this or some such standard syllabus would not necessitate the abandonment of the Elements of Euclid as a text-book by such teachers as still preferred it to any other, as it would at the utmost involve only such supplementary teaching as is contained in the notes appended to many of the editions of Euclid now in use; while it would greatly relieve that large and increasing body of teachers who demand greater freedom in the treatment of geometry than under existing conditions they can venture to adopt.’