POPULAR MISCELLANY. 



575 



would be inexplicable, and contrary to every 

 natural law and precedent, if it did not do 

 so. The force of character, strength of 

 will, clearness of mental vision, and quali- 

 ties of vigor, patience, and perseverance, 

 which constitute the secrets of success in 

 life, are the several properties of the physi- 

 cal organism, compounded as it is of body 

 and mind." A new cure is suggested, then, 

 the " health-cure," as a remedy for adver- 

 sity, which would be first personal, then 

 hereditary in its aim, aspects, and bearing. 

 The subject is worthy the attention of medi- 

 cal men and social philosophers. 



Carrying a French Meridian into Africa. 



Colonel Perrier furnishes a description to 

 " La Nature " of the manner in which the 

 French system of triangulations and the 

 meridian lines have been extended into Al- 

 geria under his direction. The idea of es- 

 tablishing a geodesic connection across the 

 Mediterranean had been entertained for 

 more than seventy years, but it was con- 

 sidered doubtful, on account of the great 

 distance from each other of the points that 

 would have to be used in the observations, 

 whether a correct measurement was practi- 

 cable. Preparations for making the obser- 

 vations were begun in 1873. Four points 

 were chosen (Mulhacen and Tetica in Spain, 

 11,53*7 feet and 676 feet above the sea, 

 Filhaoussen and McSahiba in Algeria, 3,760 

 feet and 1,876 feet above the sea), which 

 formed a quadrilateral the angles of which 

 were all visible from each other. It was 

 necessary, from considerations of climate 

 and locality, to make all the observations in 

 the latter part of the summer and the early 

 fall. Solar reflections were to be used in 

 the day, and the electric light at night, as 

 signals. The solar reflections were never 

 seen at any of the distant points, and proved 

 a complete failure. After about twenty days 

 of effort, the electric light was made visible 

 at all the points, and was used successfully 

 from the 10th of September till the 1st of 

 October, when the first series of observa- 

 tions was satisfactorily completed. The 

 calculations showed that, notwithstanding 

 the extraordinary distances apart of the 

 points of observation (one hundred and sev- 

 enty miles), the solutions were as exact as 

 in cases involving only a few miles. In 



making the astronomical projections of the 

 points, a system of rhythmic signals, or of 

 stated alternate flashes and eclipses of the 

 electric light, was employed from the 5th of 

 October to the 16th of November. It was 

 found that these signals were susceptible 

 of great precision, but that the personal 

 equation could not be disregarded in ob- 

 serving them. This equation operated in a 

 double sense, as related to the observation 

 of the stars and of the signals, in each ob- 

 server, and had to be ascertained by a series 

 of special experiments instituted in the case 

 of each person at the observatories at Paris. 

 Practically, it was a matter of indifference 

 to the observers whether they directed their 

 attention to the flashes or to the eclipses of 

 the light, but they considered the observa- 

 tions of the eclipses likely to be more exact. 

 The most convenient rhythm of signals was 

 found to be one of about two seconds, al- 

 lowing one second for the flash and one sec- 

 ond for the eclipse. The constancy of the 

 personal equation as it related to the lu- 

 minous signals was remarked, and the error 

 to be allowed for was estimated at less 

 than one hundredth of a second. 



Mr. Fleuss's New Diving-Process. We 



noticed in the March number of the " Month- 

 ly " the invention by Mr. Fleuss of a process 

 for breathing under water, which dispenses 

 for the most part with the cumbrous appara- 

 tus that divers have hitherto had to employ. 

 A fuller account of the new method has been 

 published since, in the English papers, and 

 those features of it which were then kept 

 secret have been disclosed. The power of 

 breathing depends on means which are pro- 

 vided within the helmet worn by the diver. 

 These means are designed to furnish a con- 

 tinuous supply of oxygen, and to dispose of 

 the carbonic acid which the breather exhales. 

 No provision is made for the nitrogen which 

 enters into the composition of ordinary air, 

 for this merely serves as a diluent, and is 

 not changed or diminished in quantity by 

 breathing; hence the nitrogen which is nat- 

 urally present in the diver's lungs and in 

 his dress when he puts it on can be used 

 over and over again, and is amply sufficient 

 for its purpose. The oxygen is stored in 

 the helmet in a compressed state, and the 

 supply is regulated by a valve which is un- 



