November 13, 1885.] 



SCIENCE. 



431 



Siberian branch (Irkutsk) it is learned that Sanni- 

 kow travelled on the upper Man River, following 

 it five hundred versts, to its confluence with the 

 Yenisei. He met with numerous and interesting 

 pictured rocks, all on hard, nearly vertical surfaces. 

 Later he visited the Minussinsk district, and 

 described many tumuh, statues, and peculiarly 

 disposed - stones, probably having a signification in 

 the burial ceremonies of the former inhabitants. 

 The Caucasian branch (Tifiis) reports generally on 

 the geographical work in the Caucasus. As before, 

 the Caucasian military topographical section has 

 done good work, especially east of the Caspian. 

 The telegraphic determination of longitude be- 

 tween Batum and Nikolaiew has been made. 

 Greneral Stebnitzky has prepared a large work on 

 the orography of the Caucasus. The hydrograph- 

 ical work on the east coast of the Black Sea, under 

 Admiral Zarudny, continues. Four new meteor- 

 ological stations have begun work, and it is hoped 

 soon to have two stations on the road across the 

 Caucasian chain, and one at Kars. These reports 

 also contain a large amount of information in re- 

 gard to the other geological and ethnological ex- 

 plorations going on. O. E. 

 St. Petersburg, Oct. 15. 



LETTERS TO THE EDITOR. 



♦♦* Correspondents are requested to be as brief as possible. The 

 writer's name is in all cases required as proof of good faith. 



Flood Rock explosion. 



The articles upon the Flood Rock explosion con- 

 tained in your issue of October 16, to which my 

 attention has just been called, though evidently the 

 utterances of men who are more familiar with the 

 quiet work of the study than with the varied and 

 complicated requirements of engineering practice, 

 demand an answer through your columns, in order 

 that the fair-minded portion of your readers may 

 not be misled into erroneous judgments through the 

 unjust and unfriendly remarks concerning the delay 

 in firing the mine that have been placed before them. 



The story of the Flood Rock explosion may be told 

 in a very few words. For ten years a great work 

 of engineering, costing a large amount of money, had 

 been going on, the successful accomplishment of 

 which depended upon the successful explosion, by 

 electrical action, of 290,000 pousds of high explo- 

 sives. The whole work required the most careful 

 study and forethought, to avoid accident to life or 

 limb, and to eliminate, as far as possible, the chances 

 of damage to any part of the system, upon whose 

 good order, at the critical moment, the success of 

 the undertaking depended. 



It was essential that, as soon as the mine should 

 be ready, it should be fired, for at any moment there 

 was a possibility of accident to the apparatus, which 

 would delay, if not ruin, the work of years ; but at 

 what time precisely we should be ready for the ex- 

 plosion could not be certainly predicted, though from 

 the way in which the work was progressing, we hoped 

 to be ready to fire at high water, 11 a.m. , on Satur- 



day, October 10. Work on the mine had been going on 

 night and day under the personal direction of Lieu- 

 tenant Derby, who spared himself no inconvenience 

 and avoided no danger connected with it, in order to 

 get the thing through in time ; and yet, as it happened, 

 the preparations could not be quite completed until a 

 few minutes after 11 o'clock on the day appointed, 

 when the mine was fired. I hardly need say that this 

 delay was unavoidable. 



General Abbot, who had been requested by General 

 Newton to take charge of the photographic and the 

 seismoscopic arrangements for the explosion, had by 

 personal application to the superintendent of the 

 Western union telegraph company, secured the use of 

 a wire for a short time, from the firing point at 

 Astoria to Patchogue in one direction, and to West 

 Point in the other ; and when the representative of 

 the geological survey applied to him for information 

 in regard to the explosion he offered to send chro- 

 nometer ticks to the Western union oflQce in NewYork, 

 so that they might be transmitted to the observers 

 who were not under his (Gen. Abbot's) orders. No 

 advantage was, however, taken of this offer, though 

 the Western union company would doubtless have 

 been as willing to grant the use of their wires to these 

 gentlemen as to General Abbot. 



One of our engineer points of observation, that at 

 Willet's Point on Long Island Sound, was not con- 

 nected electrically with the firing point ; the nearest 

 telegraph station being three miles distant, at White- 

 stone. Yet the young ofiicers who were detailed to 

 watch the seismoscope there, watched until they got 

 their observations, and would have watched for an 

 hour if necessary, or until notified to stop. Observa- 

 tions, it is stated, were also successfully made at 

 Columbia college, Yonkers, Princeton, and Cam- 

 bridge, though none of the observers at these places 

 were in electric connection with the firing point. 



The same degree of intelligence which secured 

 successful results in these instances would doubtless 

 have prevented Professor Paul from losing his obser- 

 vations at Stateu Island, and would have saved him 

 the discredit of having written a very ill-tempered 

 letter ; and an intelligent study on his part, of the 

 results of the explosion at Hallet's Point in 1876, 

 would have prevented him from mistaking the shght 

 disturbance which he observed, for that which 

 would necessarily be produced by the explosion of 

 nearly 150 tons of high explosives. 



If, then, there was, as has been charged, any 

 blundering or want of intelligent co-operation in this 

 matter, it is evident that it was on the part of those 

 who failed to take the necessary precautions to in- 

 sure the success of their observations, and not on the 

 part of the corps of engineers of the army, whose 

 long and honorable service has been uniformly 

 marked by an intelligent and faithful performance 

 of its duties, and by freedom from mean and de- 

 grading jealousies. 



Walter McFarland, 



Lieutenant-Colonel of Engineers. 

 New York, Oct. 28. 



I fully acknowledge that the time observations 

 upon the explosive waves from Flood Rock were a 

 matter of secondary importance, mostly of scientific 

 interest, and, even in the ' quiet of the study,' think 

 I can appreciate, perhaps not fully, but in a high 

 degree, the complicated diflBculties in the way of 



