JULV 9. 1^03] 



NATURE 



231 



The prospect of active work in connection with the ship 

 •canal across the Isthmus of Panama has directed attention 

 to the climate of the district, in which engineering work 

 •of exceptional difficulty will have to be undertaken. The 

 results are generally reassuring, and with ordinary care 

 a repetition of the horrors that accompanied the construc- 

 tion of the Panama railway need not be feared. The most 

 noticeable feature in the temperature factor is its con- 

 stancy throughout the year, the monthly range, in the 

 mean, being confined between 78° 4 and 8o°i. The daily 

 range on the coast is from 68° to 87°, and in the interior 

 from 64° to 94°. It is easy to see the effect of the oceans 

 in thus limiting the range of temperature, but necessarily 

 (here is an increase in the humidity, which is always high, 

 throughout the year. There is a great difference in the 

 rainfall on the Pacific and on the Atlantic coasts ; about 

 140 inches may be anticipated on the former, while only 

 half that amount will fall on the Atlantic side. From 

 January to April the fall is very slight throughout the 

 Isthmus, and therefore several successive months of dry 

 weather can be counted upon, which cannot but be of great 

 advantage in the engineering operations. Winds are 

 always light, and give no trouble. Greater velocities than 

 twenty miles an hour are rarely met with. The general 

 health statistics are not unfavourable. Recent inquiries 

 show that the mortality due to diseases of the climate has 

 steadily diminished since 1881, while the percentage of 

 deaths arising from European diseases has not increased. 

 Of the total death rate, 91 per cent, is due to chronic 

 organic diseases common to all countries, and only 9 per 

 cent, is chargeable to local effects. This material improve- 

 ment is due, in some measure, to the fact that the excav- 

 ations have reached a level below the poisonous emanations 

 of decaying organic matter, while, on the other hand, 

 greater sanitary precautions have reduced the effects of the 

 most deadly of the infectious diseases, yellow fever. Colon 

 has been practically free from this scourge for some time, 

 but improvements in Panama are loudly demanded. 



In the Rendiconto of the Naples Academy for April, Prof. 

 Ernesto Pascal gives the integration of a differential equa- 

 tion of Riccati's form, but of a more general character 

 than those previously considered. The right-hand side of 

 Prof. Pascal's equation contains three constant coefficients, 

 and the equations integrated by Malmst6n, Brioschi, and 

 -Siacci are the particular cases deduced by putting one or 

 other of these coefficients equal to zero. 



Vol. v.. No. i, of the series of monograph supplements 

 of the Psychological Review is a thesis by Dr. Joseph W. L. 

 f Jones on "Sociality and Sympathy." The author traces 

 the development of consciousness to the point at which 

 " consciousness of kind " emerges, and discusses the gradual 

 evolution of social relationships and the rise of sympathy 

 in any given race. 



Dr. Costantino Gorim discusses in the Lombardy 

 Rcndiconti the remarkable power e.\hibited by the typhus 

 bacillus of spreading along the surfaces of solids in contact 

 with the nutrient liquid. This effect the author considers 

 is due to the formation of filaments rather than to the 

 mobility of the bacteria themselves, but it suggests the 

 danger which may arise from watering food-plants with 

 water containing the bacteria. 



A REPORT on the dilatation of steel at high temperatures 

 is given by MM. G. Charpy and L. Grenet in the Bulletin 

 ■cli- la Sociiti d' Encouragement for May. The most notice- 

 iible features brought out in the experiments were the 

 -udden contraction at a temperature of about 700° common 



to carbon steels, the existence of a second point of contrac- 

 tion at about 300° in tempered steel containing 065 to 

 I per cent, of carbon, and of a further point of contraction 

 near 150° for tempered steels with more than i per cent, 

 of carbon, and the absence of any observed relation between 

 the dilatation-curves of nickel steel and their magnetic 

 properties. 



The eleventh volume of the Atti of the Naples Academy 

 of Physical and Mathematical Sciences contains a mono- 

 graph by G. de Lorenzo and Carlo Riva on the crater of 

 the Astroni, one of the most remarkable craters in the 

 Phlegrean fields. It derives a melancholy interest from the 

 fact that, before its completion, Signor Riva met with his 

 death in the prime of life while ascending Monte Grigna 

 from the Lake of Como. Another noteworthy feature is 

 the monograph of 220 pages on the totality of prime 

 numbers up to a given limit, by G. Torelli. 



Under the title of " Bathymeter," Mr. Leonard Murphy 

 describes in the Economic Proceedings of the Royal Dublin 

 Society a simple apparatus for gauging the depth of liquids 

 in wells and tanks. An air tube dips into the liquid to be 

 measured, and an air compressor is connected both with 

 this tube and with a reservoir of liquid into which there 

 dips a gauge glass. On working the compressor the liquid 

 in the gauge glass rises until the pressure is sufficient to 

 force the air out at the bottom of the air tube, and the 

 height of liquid in the gauge glass then indicates the 

 height of liquid in the well above the end of the tube. 



In the Annali di matematica pura ed applicata, Signor 

 T. Levi-Civita deals with singular solutions in the problem 

 of three bodies or particles which attract each other accord- 

 ing to the Newtonian law. The only case in which singular 

 solutions occur is when, at some instant of the motion, two 

 of the particles coincide ; this involves an impact between 

 the particles. The motion in which the particles are 

 approaching impact is called by the author a trajectory 

 of collision, the reversed motion being a trajectory of 

 ejection. The case discussed is that in which the bodies 

 are moving in one plane, and the mass of one is negligible 

 compared with those of the other two. 



From the Economic Journal we take the following table 

 of the ages of German university professors in the year 

 1901, quoted from an article by Dr. F. Eulenburg in the 

 Jahrbticher fiir N ationaloekonomie : — 



Age 30 35 40 45 50 55 



Number ... 2 23 124 206 256 262 



Age 60 65 70 75 80 85 



Number ... 197 194 108 36 18 3 

 where the upper figures represent ages, and the lower 

 figures represent numbers of German professors in 1901 in 

 the intervals between those ages. In 1890 the maximum 

 number was between the ages of forty-six and fifty. 



In Cosmos, M. Lucien Fournier discusses the phenomenon 

 recently described as the " flow of marble," which results 

 in a gradual bending or deformation of marble blocks, as 

 was described by Dr. T. J. J. See in a letter to Nature of 

 November 20, 1902 (vol. l.wii. p. 56). Among the theories 

 proposed to account for the effect, the actions of sunshine 

 and moisture have hitherto received support. M. Fournier 

 now suggests another possible cause — elasticity. It is 

 observed that blocks of granite frequently expand when 

 they have been relieved from the pressure of the surround- 

 ing rocks in the process of quarrying. It is now suggested 

 that a similar cause may account for the bending of the 

 blocks of marble, and this explanation would account for 

 deflections which assume a different direction from that 

 which would be expected if heat and damp were the causes. 



NO. 



1758, VOL. 68] 



