在轟轟烈烈的技术革命的热潮里,我們根据自己工作的需要,試制了几种簡單的降雨警报器,費用很少,性能灵活,效果良好,各站可以自制。现介紹于后。一:麻繩式降雨警报器: 这是利用麻繩的湿縮干漲的性能制造的。如圖一。制时选擇半旧的麻繩一段,長約5公寸,一端系于固定的木杆上,另端系于活动的鉄片上。当降雨后 In the ups and downs of the vigorous technological revolution, according to the needs of our own work, we have trial-produced several simple rainfall alarms, which cost little, are flexible in performance and work well. All stations can be made by themselves. Now introduced later. A: hemp rope rain alarm: This is the use of hemp rope wet-dry performance. Figure one. The system of choice when the semi-old hemp section of a length of about 5 inches, one end of the Department of the fixed rod, the other end of the Department in the activities of the films on the sheet. When it rains