May 9, 1890.] 



SCIENCE. 



2911 



of the house both as to temperature and moisture. The amount 

 of air is inexhaustible, the quantity in sight being sufficient to fill 

 40,000 rooms 16x18x10 feet. The opinions of many prominent 

 scientists have been obtained concerning the use of this air for 

 sanitary purposes, a few of which are here given. 



Major J. W. Powell, director of the United Slates Geological 

 Survey, in speaking of the utilization of cave-air currents for 

 regulating the temperature of buildings, says, " The phase of the 

 problem in which you are specially interested is of so great prac- 

 tical importance as to demand not only a special but a general 

 solution. It would afford me jileasure to either take up the gen- 

 eral problem or assign it to some competent authority for investi- 

 gation, were the data adequate; but there are not accessible in 

 this officeasufficient number of records concerning air- movements 

 at natural openings of caverns to render the investigation useful; 

 and. moreover, a final solution could not be reached without con- 

 sideration of just such data as you are to seek, — data which are 

 not now available. In response to your request to make sugges- 

 tions concerning methods to be pursued and results to be expected, 

 I can say but little. Indeed, I hope that you will soon be in a 

 position to convey information to me and to the ivorld at large 

 upon tbe subject." 



Dr. Billings of the Surgeon-General's Office, Washington, D.C., 

 after making several suggestions, says, "Hoping that these sug- 

 gestions will be useful to you, and assuring you that if the experi- 

 ments indicated are properly carried out they will give some 

 very interesting and valuable information, I remain 3 ours sin- 

 cerely," etc. 



Dr. Henry Henry O Marcy, Boston, Mass., after consulting Dr. 

 H. T. Boivditch, says, " Such air must be of the highest value 

 for respiratory use in diseased organs. Of course, sunshine is 

 important, and this is the chief drawback to establishing the sani- 

 tarium within the cave. To drive it by means of a fan through 

 a house would certainly seem of much value. An aseptic atmosphere 

 is the gain from the long sea- voyage or living on mountains or in 

 wooded districts. Here we ever have fluctuations in temperature, 

 and other conditions, beside moisture. It has recently been con- 

 sidered as of practical importance to furnish air to a great city, 

 as London, from high towers: why not, and much easier for many 

 reasons, from caves ? Tlie air freed from bacteria is, as you are 

 well aware, one of the secrets of success in modern surgery." 



Burton, in his '• Anatomy of Melancholy," under the head of 

 " Air Rectified " (p. 306), says, " In some parts of Italy they have 

 wind-mills to draw a cooling air out of hollow caves, and disperse 

 the same through all the chambers of the palaces, to refresh them, 

 as at Castoga, the house of Caesareo Trento, a gentleman of Vi- 

 cenza, and elsewhere." 



The only modern instance with which I am acquainted is the 

 hallof the Palace of theTrocadero, inParis. This building is erected 

 over a portion of the old stone quarries. In the course of con- 

 struction all the openings were closed, with a few exceptions. 

 When it was found that a strong, cool current came from the un 

 derground chambers, all the openings save one were closed. This 

 one was walled up to keep out the surface water, and shrub- 

 bery was planted around it. The chambers were carefully 

 cleansed and dried, and the air is permitted to enter thi'ough this 

 opening, which is never closed. The old quarries act as an im- 

 mense cooling chamber. Mr. C. H. Blackall, in a letter, says, 

 " At the rear of the stage, on the left, is a large room, the floor 

 of which is only a little below that of the auditorium, and at its 

 lowest point. In this room are the fans which draw the cool air 

 from the quarries through a large opening in the floor, and force 

 it either directly to tiie hall, as in summer-time, or first to a heat- 

 ing-chamber, where the air is warmed by passing over heated 

 pipes. The fans, air-ducts, etc., are so placed that the fresh air 

 may be introduced at the top of tbe hall, and foul air drawn out 

 at the bottom, or vice versa. The air ascends, or rather is forced 

 up, a large brick shaft behind the stage, and carried across to the 

 centre opening of the dome through galvanized iron ducts about 

 5x8 feet. 



The architect of the palace, after saying that nothing has been 

 prin cd on the subject, writes' thus: •• I have the honor to inform 

 you that the hall of the Trocadero has a capacity of about 1,620,- 



000 cubic feet; that ventilation, which furnishes 3,240,000 cubic- 

 feet per hour, is obtained by means of two engines, each of 15 

 horse power, operating two inhaling and two exhaling ventilators 

 (one of each kind for each half of the hall). These ventilators are 

 perfectly alike, they are about 8.4 feet in diameter, and consist of 

 helices of a thickness of half an inch, with eight wings at an in- 

 clination of forty-five degrees. The engines are horizontal sta- 

 tionary ones, with two cylinders on the principle of restraint and 

 condensation. Two boilers furnish the steam. Each of these has 

 a heating surface of about 189 square feet, and a capacity of 54 

 cubic feet. They are gauged to a pressure of 10 pounds. The 

 entire machinery has given excellent results. One may say it 

 works too well, inasmuch as under full power there is a great ex- 

 cess of air. Usually only one-fourth of the total possible power 

 is applied, and this is very amply suflScient." 



Taking into consideration the unlimited supply of pure, cool> 

 and, as far as investigations go, ase])tic air, together with high 

 altitude (nearly 900 feet above sea-level), its situation in the midst 

 of a virgin forest of oak and hickory, with a sandy soil (resulting 

 from the wear of the Chester sandstone) and splendid drainage — 

 indeed, every thing seems to conspire to make this a favored, 

 spot for sanitary purposes. M. H. Crump.. 



Frankfort. Ky., May 8. 



Sunspots, Tornadoes, and Magnetic Storms. 



In ray letter regarding sunspots and tornadoes, printed in Science- 

 on May 2, 1890, reference was made to magnetic storms observed' 

 at Toronto near the maximum stage of the last sun.=ipot cycle. 

 From that memorandum, by a clerical error, were omitted the 

 words "September, 1883," after "November, 1882." 



James P. Hall._ 



Brooklyn, N.Y., May 3. 



Gorse or Furze 



EuKOPEAN furze grows in one spot in the island of Nantucket,, 

 where it has maintained itself for fifty years. It was introduced 

 by an Irishman, who was homesick because it did not grow about 

 his cabin, as in the Old Country. I have never seen the plant 

 growing, but have seen branches gathered from it. I believe it 

 has not spread to any great extent. It may be interesting to some 

 that the Scotch heath also is found in one spot in the island, where- 

 it has continued for a long time. Geo. W. Perry. 



Rutland, Vt., May 5. 



Your correspondent, Mr. J. R. McGinnis, may be interested to. 

 learn that the gorse or furze (Ulex Europceus) has for many years 

 been fully naturalized in the southern part of Vancouver Island, 

 where, along roadsides and in waste places in the vicinity of 

 Victoria, it is very common. The brocmi (Sarotharwms Seoparices'i 

 is also abundant in similar situations in the same locality, and 

 both plants appear to be as much at home as in their native soil. 



George M. Dawson.. 



Geological Survey of Canada, May 5. 



BOOK-REVIEWS. 



Stanley's Kmin Pasha Expedition. By A. J. Wauter?. Phila-. 

 delphia, Lippincolt. 12°. |2. 

 If any one besides the great explorer himself is able to describe- 

 tlie progress of Stanley's eventful journey, which led to the com- 

 plete overthrow of European influence in Equatorial Africa and ta 

 the retm-n ( f the indefatigable Emin Pacha, it is Mr. Wauters^ 

 who has closely watched the progress of the expediiion from the 

 beginning to the end, and, being closely connected with the Bel- 

 gian enierprises on the Kongo, h-ad access to all the material 

 bearing on the expedition. The author begins bis graphic descrip-^ 

 tions with a history of the conque^t of the Soudan and the revolt 

 of the Mahdi. which was the immediate cause of the ditfic-ulties 

 with which the governor of the Equatorial Province was beset. The 

 first half of the book is taken up by descriptions of the state of 

 affairs in the Scudan, Dr. Junker's injportant expeditions and his 



