n6 



KNOWLEDGE & SCIENTIFIC NEWS. 



[July, 1904. 



strong enough for the work. By constructing the wings 

 on this principle, instead of so staying them as to be 

 rigidly liorizontal, an advantage was gained in that while 

 on the track the ends were not caught by any side wind, 

 and yet, while supported in the air, a considerable diedral 

 angle was formed which gave the desired transverse 

 stability. On June 13, some larger aeroplanes were 

 fitted. These were of hexagonal shape (being, in fact, 

 constructed of old man-lifting kites), and were each of 

 118 s()uare feet area. The arrangement may be seen in 

 the last photograph. The lower end of the track had 



feet was spread in front of the same hexagonal aeroplanes, 

 and some fairly successful glides were made, although, 

 of course, the weight per area (i'24 lbs. per square foot) 

 was still very excessive when compared to the propor- 

 tions which previous experimenters with aeroplanes have 

 applied. 



Now that the general arrangement and practical 

 working of the apparatus has been well tested, it will be 

 possible to make more exact trials. It is proposed to fit 

 on an upper aeroplane and other additions to make the 

 total supporting surface up to some 430 square feet, and 



Paddling Ashore After Descent 



lPli,>lv ly himell. 



now been altered by removing the end support so as to 

 allow the ends to droop. This is shown in the two 

 photoijraphs of the apparatus in the air, the boards 

 having sprung back into the horizontal position after 

 having been depressed by the weight of the boat. As 

 the boat left the track, it was canted forward so 

 that it shot downwards into the water too abruptly 

 to make a good glide. There was, moreover, on this 

 ocasion a considerable head wind, which often in- 

 terfered to some extent with the apparatus attaining 

 a good speed, but which was not found to be so 

 serious as might be thought. The usual time of descent 

 from the top of the track to the take-off was just 

 3 seconds, being sometinii-s extended to 3^ seconds. On 

 June 18 further trials were made, after a number of minor 

 improvements had been effected. The lower end of the 

 track was now rigidly supported and set so as to be 

 exnctiv horizontal. A triangular "beak" of iS square 



it then seems probable that we may be able to make some 

 useful glides, full accounts of which 1 hope to send in for 

 the next number. 



Chicago is considering a new machine tO' mend the holes 

 which all too frequently make their appearance in 

 asphalt streets. A committee has g^one to Pittsburg 

 from Chic;igo toi test the device, and if it proves tOi be 

 able to do what is claimed for it, it will proliably be 

 adopted in, other cities besides Chicago. .'\spha!t mend- 

 ing as it is done at present is both a tedious and ex- 

 pensive job, and a machine which would do' good work 

 automatically would find a ready field. 



