25-2 



SCIENCE. 



[Vol. II., No. 29. 



direction of them in any place. He had made some 

 observations on a line of his own, half a mile long, 

 and had invariably found that in that line the current 

 is in one direction ; audits electro-raotive force varies 

 from about one-tenth of a volt up to three volts. 



In regard to these lines, said President Rowland, 

 quick flexures of that sort must be due to local causes. 

 They cannot be due to any thing at the centre of the 

 earth. With respect to using a line in determining 

 eai-th-currents, I think it is unsatisfactory. I do not 

 believe very much in it, myself. Ton can get a cur- 

 rent in the line, but you are not certain it is in the 

 earth. 



A member remarked that in ISSl, in Boone County, 

 Missouri, he had a line in which a continuous current 

 was evinced with an electro-motive force of from two 

 to four volts. From 8 to 10 in the morning was the 

 maximum, and 5 p.m. the minimum. The line being 

 east and west, the direction of the current was from 

 east to west. 



President Rowland said : If you put the wire on the 

 earth's surface from one point to another, you mere- 

 ly determine the difference of intensity between those 

 points. It shows there is a current there when the 

 wire is there, but not when the wire is not there. 



A method of distributing weather forecasts by 

 means of rail-wrays. 



BY T. C. MENDENHALL OF COLUMBOS, OHIO. 



This system has only been in operation in Ohio for 

 about a year. To distribute forecasts, we place signals 

 upon the sides of the baggage-cars, as distinct as 

 possible from each other, so as to be easily recog- 

 nized at considerable distances, and also to convey 

 as much meaning as possible, so as to predict as 

 many different conditions. We adopted a combi- 

 nation of form and color. The signals are three 

 in number as to form, and two In number as to 

 color.' The red signals are confined to predictions 

 as to temperature, — rise in temperature, stationary 

 temperature, falling temperature. The other color 

 is blue, and that is confined to predictions in 

 regard to the general state of the weather. The 

 question of form was a good deal considered, and 

 tliree forms were adopted. We adopted the sun, 

 moon, and star, because everybody was familiar with 

 those words. We experimented with tlie triangle, 

 and finally rejected it. The device for attaching to 

 the car is due to Mr. Anderson, who has been in the 

 service of the board of commissioners for the past 

 year; and it is a really happy device. The signal is 

 made as large as possible, and the disk can be seen a 

 long distance. .The red sun and blue moon mean 

 higher temperature and general rain. The crescent 

 means lower temperature ; the full disk of blue means 

 general rain; the star represents local rains. With 

 regard to the proper working of the system, though 

 it has been in operation but a short time, it has 

 really done good work. We receive special telegrams 

 every morning, and they are transmitted to the train- 

 despatcbers at five o'clock. We are as yet operating 

 it only on one railroad. It happens, fortunately, that 



that road goes through an agricultural region of con- 

 siderable importance. It is the road connecting the 

 cities of Columbus and Cleveland. Two trains start 

 out in the morning, at the middle point between 

 those cities. The signals are put (m the cars at five 

 o'clock in the morning; and as they run through the 

 morning hours, the farmers along the line can have 

 an opportunity of seeing them, and predicting th« 

 weather for the day. The railway company circu- 

 lated through the whole line little cards, having 

 these signals displayed in colors, with their meaning 

 in every combination. This helps us, because it en- 

 ables everybody to understand what is meant. A 

 recent communication from Gen. Hazen indicates a 

 disposition on the part of the general government to 

 take hold of the matter, and bring it into general 

 operation as far as possible. Postal-cards have been 

 sent to various persons along the line, with questions 

 in regard to the practical working of the system, 

 which are answered and sent in at the end of every 

 week; and we find, that, on the average, SO percent 

 of the predictions are verified. 



Flan for a state -weather service. 



BY F. E. NIPHEB OF ST. LOUIS. MO. 



While a good many are accommodated by the 

 weather-signals which Professor Mendenhall has 

 already inaugurated, many live a distance from the 

 railroad, and cannot be interested in a scheme which 

 makes it necessary to travel eight or ten miles to learn 

 about the weather, because they might be interested 

 in a different kind of weather by the time they got 

 home. The information might be most easily circu- 

 lated by telegraphing from picket-stations to the west- 

 ward. There might be a line of stations on the rail- 

 road north and south; and stations might be found 

 necessary in Nebraska, which would give immediate 

 warning to the central office whenever it began to 

 rain at the station ; and a code might be arranged, so 

 as to give the idea of the operator as to the probable 

 violence or duration of the rain. Of course it would 

 be necessary to make special study of the general 

 laws for the progress of summer rains. Supposing 

 the information is telegraphed to the central station, 

 the predictions can easily be made out as soon as the 

 picket-stations could be reached, and a clear idea ob- 

 tained as to the probable, direction of the storm, and 

 the time at which it would reach the different por- 

 tions of the state. That information could be trans- 

 mitted by the railway companies. Finally, we should 

 make more intimate connection between these and 

 private telegraph-Jines which can be constructed by 

 the persons who are to be served with the weather- 

 signals. This plan contemplates the erection of pri- 

 vate telegraph-lines leading in from the country to 

 the stations. Upon a twenty-mile line, which would 

 be a frequent length in Missouri, ten fanners will 

 have to pay for the erection of a couple of miles 

 of wire, and the instruments, which can be put up 

 for $30 a mile. Some person could be sent from the 

 vicinity to the director of the service, and instructions 

 given him in regard to the manner of operating the 



