September i, 1893.J 



SCIENCE. 



ti^ 



is a question of only a few years before all our great 

 trunk lines, or, in fact, all lines running trains at high 

 speed will be thus protected. The earlier forms of block 

 systems comprised a semajjhore for each track, controlled 

 from a cabin or tower at the entrance to each block or 

 section. Telegraphic communication was established be- 

 tween these towers, and the movement of trains thus 

 pretty well controlled, of course always assuming proper 

 vigilance and devotion to duty on the part of the tower 

 men and engineers. Nevertheless, accidents have hap- 

 pened by reason of a signalman forgetting that a train 

 has lately passed his tower, and allowing another to fol- 



FIG. 3. 

 low it, without any information from the tower ahead. In 

 the latest systems brought into use, the danger of such 

 carelessness is largely, if not entirely, overcome, by inter- 

 locking the signal levers in two successive towers. By a 

 combination of mechanical and electrical devices, each 

 lever that moves a signal is locked in position by the man 

 in the tower at the farther end of the block section, and 

 can be unlocked only with the latter's consent and co- 

 operation. For example, in fig. 3, a signalman at H can- 

 not lower his signal to "safety," in order to admit a train 

 to the block ahead, without asking the operator at the 

 next tower, J, to unlock his {H's) lever. The man at / 

 will not do this unless he knows that the block or section 

 H-I is clear. A train having passed /, going towards K, 

 and protected by a danger signal at /, the signalman 

 there, on request of H, will unlock the latter's signal 



A 



FIG. 4. 



lever, so that he can lower his semaphore to safety, and 

 admit a train to block R-I. It is usual, also, to have each 

 signal in duplicate; that is, a semaphore placed from 1,200 

 to 1,600 feet in advance of the one at which an engineer 

 must stop, if it stand at danger. The latter is called the 

 "home" signal; the former, the "distant" signal. Home 

 signals are almost invariably painted red, and of the 

 form shown in fig. 1. At night they display a red light 

 when the blade is raised to danger j)osition. Distant sig- 

 nals are made of the "fish-tail" form, as shown in fig. 4, 

 and painted green or, rarely, yellow, displaying a green 

 light at night when raised to indicate "caution." A dis- 

 tant signal is for the purpose of informing an engineer 



whether he will find the home signal at danger or not. 

 In moving the blades to indicate danger, the distant is 

 first raised, then the home signal. In lowering them, 

 however, the reverse order is used. If an engineer finds 

 the distant signal lowered for him, he can go on confi- 

 dently without slackening speed, knowing that he has a 

 clear block ahead. If, however, it is against him, he then 

 has time to bring the train under control and come to a 

 dead stoj) on reaching the home signal, which, if at dan- 

 ger still, he must under no circumstances pass. In the 

 Fourth Avenue tunnel. New York City, the signals are ar- 

 ranged so that the act of moving a signal to danger, 

 places a torpedo on the rail over which the train must 

 pass, and in addition to this, a gong is set loudly ringing 

 if an engineer, neglecting the ordinary signal, runs be- 

 yond a certain point. Setting the signal to safety again 

 removes the torpedo and throws off the gong mechan- 

 ism. These extra safeguards have been found to be 

 absolutely necessary in this place, where the traffic is so 

 dense and the conditions of working are so trying. 



ALTITUDE IN SPITE OF • HUIillDITY AS A CUEE 

 OF BEEI-BEEL* 



BY ALBERT S. ASHMEAD, M. D., NEW YOEK. 



The Hakone Mountain resorts, 836 metres above sea- 

 level, Karuizawa, the new foreign resort, the religious sta- 

 tions (ten) disposed on each of the four roads ujd the sacred 

 Fuji Mountain, and the Ikao Mountain and hot springs 

 resort at Nikko, are the main beri-beri resorts of Japian. 

 All these are in the neighborhood of volcanic centres. 

 Karuizawa, at the head of the Usui Pass, is 3,000 feet above 

 sea-level. Its mean temperature is 8° lower than that of 

 Tokio, in the principal Kakke month, August; and there 

 is a mean oscillation of 20° P. in the temperature of the 

 day, as compared with the night. While at Tokio the 

 variation is only 14°. It is this coolness of the nights, in 

 all the mountain resorts of Japan, which makes the heat 

 of the day tolerable. The August humidity, in all the 

 mountains of Japan, although they have three times the 

 rainfall of Tokio, is practically the same as in the latter 

 city. 



Yamanaka, another resort in the Hakone Mountains, is 

 higher even than Karuizawa, the same conditions as 

 above. 



Fuji, the i)eerless mountain of Jajjan, is 12,238 feet 

 high. Its slopes are cultivated to an elevation of 2,000 

 feet. It can only be visited in the Kakke season, July 

 and August. At other seasons, it is too cold. The highest 

 temperature that has ever been recorded in August, on 

 the summit of Fuji, was 70.5°, and the lowest 31.1°. The 

 mean daily range of temperature is a little higher, 20.9°,- 

 than at Karuizawa; that is the variation between day and 

 night. There are at the top of the mountain thirty-six 

 inches of rainfall, and three-fourths of the whole quan- 

 tity belong to the three or four days of the first storm of 

 the month. The influence of Fuji in encouraging precijsi- 

 tation, is shown also at Karuizawa, the latest beri-beri 

 resort, and in the other resorts.' 



The comparison between the three, top of Fuji, Yaman- 

 aka on the Hakone IMountains, and Karuizawa, gives the 

 following figiu'es: 



Rain- Rainy 

 Bar. Range. Temp. Range. Vap. Hum. fall. days. 



Top of Fuji 490.7 13.1 7.7 11.6 5.5 71.2 SSS.i iS 



Yamanaka (Hakone). 677.5 ii-8 20.6 g.6 i6.o 88.7 5S0.4 iS 

 Karuizawa 679.1310. 21.3 11. i 16.0 86. 212.0 17 



*Communicated to the Sei-I-Kwai, or Society for the Advancement of Med- 

 ical Science in Japan. 



lAshino-yu is at Ubago, near the base of Fuji. Hakone Lake is 

 separated from Fuji by a ridge. Yamanaka Lake is seen from the top of 

 Fuji. The same influence operates at Ikao; this is near Asama-yama, the 

 second highest volcanic peak in Japan (Shinano.) 



