TRAVELING AT HIGH SPEEDS HELE-SHAW. 639 



of seawortliiness. The rate of progress in the increasing speeds in 

 this class of boat is shown on a separate curve (fig. 4), from which 

 you will see that the celebrated Miranda held as a hydroplane the 

 record with the Tartar for speed, the Ursula also holding the record 

 of about the same speed as a motor boat. Only a few days ago, how- 

 ever, the new boat Maple Leaf III has attained the extraordinary 

 speed of nearly 50 knots; that is to say, a speed approaching 60 miles 

 an hour, using 600 horsepower to effect this speed. To use a vulgar 

 expression, this certainly smashes all previous records for speed. I do 

 not pretend to give exact figures in this case, because such have not 

 been officially taken, but the statement is probably on the low side as 

 the boat has not been yet properly tuned up. You will see one 

 remarkable thing from the curve, namely, that the rate of progress has 

 been so rapid in this class of boat, and the curve rises so steeply, that 

 in about three months' time there is due from Sir John Thornycroft a 

 boat which will travel at about 100 miles an hour. I am afraid, how- 

 ever, it would not be fair to press this graphical argument quite so far. 



Through the kindness of Sir John Thornycroft and Mr. Edgar, the 

 owner of the Maple Leaf, I am able to show both the Miranda and 

 the Maple Leaf III. The latter, you will see, is traveling at such 

 an extraordinary rate . that the water which is lifted up does not 

 fall to the surface again until the boat itself has traveled several 

 lengths away. You may be interested to see a model of this last boat, 

 which has been kindly prepared for me to show to-night, as well as the 

 Tartar and Miranda. You will notice the form of the Maple Leaf 

 III is that of a steeped hydroplane, which in a modified form was 

 first suggested by Mr. Eamus many years ago; it is the secret of 

 placing the weight, and also the development of light engines giving 

 large horsepower, which has enabled the dream of Mr. Kamus to be 

 fulfilled. 



Turning to the last of the three elements, namely, air, it was my 

 intention to have dealt with it at greater length than I now find it is 

 possible to do, but, thanks to the daily press and illustrated journals, 

 this subject is as fresh in the minds of everybody as it is familiar. It 

 is not necessary in this room to remark that the wild talk of almost 

 incredible speeds has very little foundation. Bodies move quickly 

 enough in the air, and very often far too quickly, but what is gener- 

 ally overlooked is that the difficulty of the problem lies in the matter 

 of supporting the body in the air rather than moving through it, a 

 problem which is very much simpler for land and water. The 

 human body itself, while of about equal specific gravity with water, is 

 about 800 times as heavy as air, and probably, taken in conjunction 

 with the motor and aeroplane, the weight which has to be supported 

 is several thousand times as heavy relatively to the air which it dis- 

 places. Inasmuch as the support of the air necessitates the use of an 



