Page:Popular Science Monthly Volume 30.djvu/269

 Rh nets should extend over the whole area of each country. Neither the topographical necessities nor the scientific requirements make such a complete geodetical survey indispensable. Those countries possessing a comparatively larger territory would find a complete triangulation too costly and too slow. Each country has therefore laid its nets as it thought best. The Atlantic countries, France and Spain, have laid a series of parallel nets from north to south, and another from east to west, crossing each other almost at right angles. Supposing each of these nets to be drawn on the map, but instead of the various triangles a thick black line to be laid down as a sort of central line of each separate net, the whole systems would have the appearance of square grates or pigeon-holes. Germany and Austria have not observed the same rule; their lines are less regular in form, although just as convenient for the purpose. Italy and the smaller states have found it necessary to cover their whole territory, on account of their irregular geographical form, or their smallness. Sweden and Norway have run several nets, and also Russia; but the vast area to be covered leaves a thorough and systematic triangulation of the whole country out of the question.

The control which observations extending over such a vast area permit is very great. The possibilities of its being extended over a still wider field are only limited by political difficulties and by the great cost necessary for its execution in half-civilized countries. The result of the work undertaken by the International Commission can not fail to be of the highest scientific value, and the standing of the men who compose it is a guarantee that the greatest efficiency and thoroughness characterize the work done.

Of the calculations necessary, and which follow the field-work, the least said the better. To an outsider, one who is incapable of comprehending the scientific purpose of the same, they look very much like time wasted and which could have been better employed. It will suffice to say that all calculations are made twice and independently of each other. Each set of calculators do their work independently of the other, and only compare the final result. Months and months elapse before a partial result is reached, and before other and more complicated calculations can be begun. But the battle-field is one worthy of man; he has arrayed himself against figures, and, although slowly, he conquers them with the help of formulas, equations, and logarithms, all children of his fertile brain. The scientific result is obtained with scientific means. From beginning to end, geodetical triangulation is purely scientific; nothing is left to chance, and, although it can not by any means be mathematically precise, it comes as near the point of complete correctness as it is possible for any human thing to be.