True Figure Research Articles

THE VALUE OF HUMAN LIFE

r; aG?j ANY attempts have been made to estimate the money value of human life, some of the most careful by members of this Association. The usual point of view is to consider that the money value of a life i represented by its value to its possessor, or to his 2kn!3 ~family. Most hygienists count the money value of life in terms of earning power or wages. To the individual and his family his earnings are indeed the most urgent economic factor of life and it is natural that this viewpoint should be first in the minds of most of us. Though it does not take into consideration the very great economic importance of the non-wage-earning work of wives and other housekeepers, an estimate of wages lost by sickness and death does serve to illustrate the enormous dimensions and importance of the problems which the hygienists have to solve. According to this view, the capital value of a human life varies according to age, depending as it does on the two factors of earning capacity and expectancy of life. How much does a person earn and how long will he live? The answers to these questions will enable us to state how much he is worth. Years ago, Farr, in England, estimated that the new-born babe of an agricultural laborer was worth $Z5, and figured out an increasing value up to middle life, after which the figures slowly declined. Fisher, assuming $700 as the average annual earnings of all workers in the United States (though he asserts, and probably correctly, that $i,ooo is nearer the true figure), calculates that the value of a wage earner varies from $90 at birth to a maximum of $4,I00 at 30 years, sinking again to $z,900 at 5o. He further estimates, by using the census figures for age distribution, that the average economic value of the inhabitants of the United States is

An improved method for opsonic index estimations, involving the separation of red and white human blood corpuscles

Opsonin is the name given by Sir A. E. Wright to the substance in human blood which mainly influences phagocytosis. In order to measure the opsonin, equal volumes of normal serum, of a bacterial emulsion, and of leucocytes are incubated to promote phagocytosis, and the number of bacteria visible in a random sample are counted in a stained film preparation. By repeating the experiment with a pathological serum, a ratio is obtained which is known as the opsonic index. The method, however, has been found inaccurate, and consequently fallen almost into disuse. Drs. Greenwood and White pointed out the error of random sampling and, after elaborate mathematical analysis, adjudged the “liability to error” on a single count to occasionally exceed 20 per cent, from the mean or true figure. Clearly, when the counts from two films are contrasted, the liability to error may be doubled. This liability to error is due to the variation in content of different leucocytes in the same film ranging from 0 to 25 bacteria, and the resulting total in 50 leucocytes will vary according to the field in which the operator happens to make his count, i. e ., one rich in high or low contents.

The Fleet of Xerxes

Two extreme views obtain as to the numbers of this fleet. Many modern writers have unaffectedly accepted, sometimes with conviction, the 1,207 (or 1,327) triremes of Herodotus. In sharpest contrast, we have Prof. Hans Delbrück's estimate of not over 300 triremes for Xerxes' fleet at the outset, or anyhow at Artemisium. Delbrück discards all Herodotus' numbers as equally worthless, and sets out to deduce the true figure from criticism of the naval battles and of probabilities; it leads to the result that at Salamis the Persians were actually outnumbered, which is the point that really matters. Several intermediate views have also been put forward; Dr. H. Welzhofer and Prof. J. Beloch have taken the figure as 1,207 ships, not warships, Welzhofer putting the warships at something over 400; Prof. J. B. Bury and Dr. J. A. R. Munro have suggested 800 triremes at the outset; while Dr. E. Meyer gives 600–800 to start with, not all triremes, and 400–500 at Salamis, the fleet being brought up by transports, etc. to the popular figure of 1,000. Naturally, most of these figures are guesses from the probabilities of the case; but Dr. Munro has recognised the crucial fact of the four divisions of the fleet.

Bimetallic Mirrors Made by Electro-Deposition

APROPOS of Mr. Cowper-Coles's exhibit at the recent soiree of the Royal Society of metallic searchlight reflectors made by the electro-deposition of copper upon a silver film chemically deposited on glass, it may be interesting to mention that some forty years ago (I think in the year 1865) I spent a considerable time in experimenting in the same direction. My object was to make a true “flat” for the second reflection of a Newtonian telescope, with silver surface as bright as that in contact with silvered glass and without degradation from the true figure of the glass. The last condition I was unable to fulfil. It had been rightly judged that the outside surface of the silver film used by M. Foucault could scarcely have the truth of figure or the brilliancy of polish of the glass on which it had been deposited, hence the desirability of the object sought.

Recent and Proposed Geodetic Measurements

IN the history of geodesy and the discussion of the problem of the figure of the earth, the measurement of three arcs of meridian stands out conspicuously. These are the Peruvian and Lapland arcs in the Northern Hemisphere, and that of Lacaille in the neighbourhood of the Cape of Good Hope. Those who took part in the original measures worthily distinguished themselves, but it is inevitable that with the demand for greater accuracy in geodetic inquiries the necessity for repeating the ancient measures should be acknowledged. Without experience and with imperfect instruments, it is remarkable that the old astronomers accomplished what they did. To determine the approximate figure of the earth, and to derive a fairly accurate value of the compression was no mean achievement. But Lacaille's arc of meridian soon fell into disrepute, and other measures have had to be substituted by Maclear and others. Svanberg repeated the original work of Clairant and his colleagues, in Lapland, soon after its completion, and within these last few years a new determination of the Peruvian arc has been imperatively called for. There is no doubt but that the French nation, who have so honourably distinguished themselves in the difficult task of geodetic measurement, will be able to undertake this work, and increase their scientific reputation. From 1734, when the enlightened Government of the day undertook the measurement of two of the aforementioned arcs, down to our own time, when we have seen the Mediterranean successfully bridged by a geodetic survey, and the interior of Africa connected in one unbroken chain with our own Shetland Islands, French men of science have played a conspicuous part in all questions connected with the true figure of the earth. At a moment therefore when the re-measurement of the famous arc of Peru has been forced upon us, it would have been with a feeling akin to disappointment if we did not find the French nation eager to repeat the historic work with all the skill1 that long experience has suggested, and all the accuracy that modern science demands. The report of a committee of the French Academy of Sciences, however, assures us that the ardour displayed by the French in the past is no whit abated, and that though the sacrifice of time and money is considerable, these drawbacks will be cheerfully, borne. For the arc in Lapland another has been substi-stuted on the Island of Spitsbergen, and the necessary work of triangulation has been for some time quietly carried on under the auspices of the Russian and Swedish Governments; while at the same time, the reports of Her Majesty's Astronomer at the Cape of Good Hope tell us what is being done in the way of supplementing Lacaille's arc in the Southern Hemisphere. With this activity before us, it seems a fitting opportunity to. compare the aims and the motives that inspired those who-inaugurated the earliest geodetic expeditions with those that will influence and guide the latest surveys in the-same or similar regions.

The true figure of the Earth

The true figure of the Earth

XIX. On the correction of a pendulum for the reduction to a vacuum: together with remarks on some anomalies observed in pendulum experiments

The great importance which has, of late years, been attached to experiments on the pendulum, is evinced not only by the repeated and valuable labours of several of the most distinguished mathematicians and experimentalists of the present age, but also by the numerous scientific voyages that have been undertaken by several of the European Governments, with a view to ascertain and compare the results of different pendulum experiments made in various parts of the globe ; and thence to determine the true figure of the earth. These results, or the number of vibrations which are made in a mean solar day, whether made by the same, or by different pendulums, were considered, till within these few years, as strictly comparable with each other by means of certain well known corrections; whereby they were reduced 1° to arcs indefinitely small, 2° to a common standard of temperature, 3° to a vacuum, and lastly to the level of the mean height of the sea.

XI. Observations made with the invariable pendulum (No. 4. Jones), at the Royal Observatory, Cape of Good Hope, for the purpose of determining the compression of the earth

The important problem of ascertaining the ellipticity of the earth has, for a long time past, drawn forth the talents and labours of some of the most scientific men in Europe; and it still continues to be deemed an object of especial regard by all who feel an interest in the promotion of natural knowledge. To attempt to depict the strenuous exertions, the innumerable fatigues, the ardour for the improvement of science, which actuated so many illustrious persons in endeavouring to discover the true figure of the earth, would only be a waste of time; as learned Societies have always recognised and stamped the due meed of merit to each, and invariably appreciated and published to the world the valuable results which have with so many difficulties been obtained. The nations of Europe, emulous of each other in a work which particularly distinguishes the acquirements of modern times, have encouraged and laudably given their protection and sanction to eminent individuals engaged in undertakings so conducive to the honour of an enlightened community.

VII. Considerations on the convenience of measuring an arch of the meridian, and of the parallel of longitude, having the observatory of Geneva for their common intersection. By Mark Augustus Pictet, Professor of Philosophy in the Academy of Geneva; in a letter to Sir Joseph Pictet, Bart. P. R. S

Sir, The accurate knowledge of the dimensions and true figure of the earth is not a matter of mere curiosity. Astronomy and navigation are so closely connected with it, that the philosophers of the present century have pursued this enquiry through the most discouraging difficulties; and governments themselves have contributed considerable sums towards its success.

XIII. An easy method of procuring the true impression or figure of medals, coins, &c. humbly addressed to the Royal Society

It must, I believe, be thought an agreeable and useful thing, to be able to print off an exact and fair picture, or representation, upon paper, of any medal, coin, or seal, one may happen to get the command of for a few minutes, without doing it the least Injury, and with very little either of expence or trouble.

I. The longitude of Buenos Aires, determin'd from an observation made there by Pere Feuillèe

I have as Occasion offered, made it my Business to collect such Celestial Observations as might be of Use to determine the Longitudes of Places on the Sea coast of World; in order to get as near as possible the Out-line, or true Figure of the Earth, without which our Geography of the Inlands must necessarily be very insufficient.