594 



NATURE . 



[October 22, 189: 



RAIN-MAKING IN TEXAS. 



IN Nature of September 17 (p. 473), Mr. H. F. Blan- 

 ford has discussed at considerable length the rain- 

 making experiments in Texas, on the basis of such 

 information as was attainable from newspaper reports. 

 Inasmuch as these telegraphic reports have not only been 

 inadequate, but also frequently inaccurate and mislead- 

 ing, the writer, who was the meteorologist of the Expedi- 

 tion, is led to give the following brief summary of the 

 experiments and their results. 



The experiments, which have been quite independent 

 of the direction or patronage of the Weather Bureau, 

 have been carried on by the Hon. R. G. Dyrenforth, Spe- 

 cial Agent appointed by the Department of Agriculture. 

 The plan of exploding oxy-hydrogen balloons was 

 adopted as one of the principal methods to be employed, 

 and several months were spent in preparing the necessary 

 materials and apparatus. Preliminary experiments made 

 in Washington demonstrated that a tremendous concus- 

 sion could be produced by the explosion of balloons 10 

 feet in diameter, filled with a mixture of hydrogen and 

 oxygen in the ratio of two to one. In addition to the 

 explosion of balloons, preparations were made to fire 

 sticks of dynamite carried up in the air by kites, and to 

 explode rackarock (an explosive consisting of three parts 

 of potassium chlorate to one part of nitrobenzol) and 

 dynamite on the ground. 



With materials for carrying out these three lines of 

 experiment, the party went to an isolated ranch twenty- 

 three miles north-west of Midland, Texas (lit. 32° 14', 

 long 102° 12'). The inauguration of the experiments 

 attracted great attention throughout the whole south- 

 western section of the country, and, locally, people went 

 from all the surrounding counties to witness the opera- 

 tions. Actual trial in the field soon developed the fact 

 that the preparations for the balloon experiments were 

 entirely inadequate. Accidents occurred to the furnaces 

 for generating the gas, which took much time to repair, 

 windy weather prevented the filling of the balloons, and a 

 combination of other sources of delay rendered this line 

 of experiment a practical failure. One or two balloons 

 were exploded on several days, but these were too 

 few in number and too infrequent to serve the purpose 

 of an adequate experiment. Similarly it was found im- 

 possible with the small available force to operate the 

 kites to advantage, and in windy weather they were quite 

 unmanageable ; so that, although, in all, quite a number 

 of dynamite sticks were fired in the air in this way, yet 

 as a line of effective experiment this also proved a failure. 

 The only explosions that were made on a scale even 

 approximately commensurate with the requirements were 

 those of rackarock, and it may be stated that all the 

 effective operations essential at Midland can be dupli- 

 cated in every essential particular with 1500 pounds of 

 rackarock together with 500 feet of wire and a small 

 portable dynamo. 



The first rain that occurred after the party reached 

 Midland began shortly after noon on August 10, and con- 

 tinued at intervals until evening. The amount of rainfall 

 was not measured, but it was stated in the language of 

 the country to be a good "grass rain." The writer, who 

 was ett route to Midland, met similar sharp showers in 

 the latter part of the afternoon near Sweetwater, 100 

 miles to the eastward. On the preceding evening some 

 preliminary explosions had been made, but only on a 

 small scale, and no result was anticipated. In the tele- 

 graphic despatch that was sent reporting the rainfall, no 

 causative action was claimed — in fact, such action was 

 explicitly disclaimed in the telegraphic report, which 

 stated " we do not think the explosions actually produced 

 the storm, as they were not on a large enough scale. 

 The preliminary trial was made simply to test the 

 efficiency of the special blasting powder." The firing, 



NO."lI4 7, VOL. 4A] 



which was not over half-a-dozen blasts, was, then, simply 

 a preliminary trial of material, and not in any sense an 

 experiment to produce rain. 



On August 16, 17, 18, and 20, cloudy weather very 

 largely prevailed, and numerous thunderstorms were seen 

 on the horizon that did not visit the ranch. ( n each of 

 these days blasts of rackarock and of dynamite were 

 fired while heavy cumulus or dense storm-clouds were in 

 the field. In several instances, when a dense threatening 

 cloud was overhead, a sharp detonating explosion of 

 rackarock or of dynamite was followed at an interval of 

 30 to 40 seconds by a spatter of rain, or, if it was already 

 sprinkling, the blast was followed by a very noticeable 

 increase of the drops. This interesting result occurred a 

 sufficient number of times to indicate that the pheno- 

 menon was a real effect of the explosions. On none of 

 these days, however, was the amount of rainfall appre- 

 ciable, except on the i8th, when it was two-hundredths 

 (o'02) of an inch. The 18th opened cloudy, and old 

 settlers predicted rain for the afternoon, whether the 

 experiments should be made or not. To what extent, 

 therefore, the explosions that were made were influential 

 in producing the 002 inch that fell is obviously very 

 difficult to determine, and as an evidence of the efficacy 

 of the explosions it is practically valueless. 



The next explosions were on the evening of August 

 21, when 156 pounds of rackarock were fired in 14 

 blasts. During the night a genuine norther came on, 

 the wind blew from the north, the barograph curve rose 

 rapidly, the temperature fell rapidly, and during the next 

 forenoon a fine mist prevailed. This change of weather 

 was quite extraordinary and unexpected, and with its 

 accompanying mist was attributed to the heavy firing 

 of the evening previous ; but the norther had been on 

 its way for several days, and the fine mist was evidently 

 due to the uplifting by the cold north wind of the warm 

 moist, air of the plains. At numerous points in the 

 State where the air was more humid a heavy rainfall 

 occurred. 



The last experiment, which in magnitude was the 

 greatest of all, took place on the evening of August 25, 

 after the writer had departed. The conditions were 

 thought to be extremely unfavourable for rain, and the 

 party was advised to wait for a more propitious occasion. 

 The firing, however, was carried on until 11 p.m., when 

 the party retired for the night. It is reported that " at 

 3 a.m. the heavy rolling.of thunder disturbed the sleepers, 

 heavy banks of clouds were seen advancing, almost con- 

 stantly lighted by most brilliant lightning. An hour later 

 the rain began to fall in torrents on the ranch, and did not 

 cease till 8 a.m." Unfortunately, records of the amount 

 of rainfall have not yet been received, but 1 am informed, 

 by a gentleman who was present, that "it was nothing 

 but a sprinkle." Further light is thrown on this rainfall 

 by the weather map for 8 p.m eastern time, of August 

 25. Rainfall is shown in New Mexico to the north-west 

 of Midland, Texas, and the forecast officer made the fol- 

 lowing prediction : " For Eastern Texas, generally fair, 

 except local showers on the extreme south-east coast 

 a?td the 7torth-west.^' Here we have an official pre- 

 diction made in Washington City of probable showers 

 over the district in which the experimenters were 

 operating, and for the very night in which the thunder- 

 storm followed the last of the explosions to produce 

 rain. 



In view of these facts, it is scarcely necessary for me 

 to state that these experiments have not afforded any 

 scientific standing to the theory that rain-storms can be 

 produced by concussions. But, if the adherents of the 

 theory maintain that " no experiment has been tried that 

 is worthy of the name, and that no results ought to be 

 looked for," it will be difficult to take opposite ground. 

 Geor(;e E. Curtis. 

 Smithsonian Institution, October 9. 



