166 



Popular Science Monthly 



A small Niagara 

 which has been de- 

 veloped indoors as 

 a part of the hy- 

 draulic laboratory 



It takes a power 

 plant of 500 horse- 

 power (see photo- 

 graph at the right) 

 to make the mini- 

 ature Niagara 



also commercial forms and 

 sizes of turbines under large 

 energies of water may be 

 studied. The whole ap- 

 paratus is fitted with meas- 

 uring devices so that precise 

 measurements may be made 

 at any point. One engineer 

 who inspected the outfit said, 

 "This is using a river and 

 measuring its effects with a 

 teaspoon," so delicate are 

 the tests applied. 



In the basement of the 

 school there are eight hun- 

 dred feet of canals supplied 

 from the Charles River Basin. 

 These have turns and 

 narrowings and junc- 

 tions, so that the flow 

 may be observed under 

 all possible conditions. 

 The outfit includes many 

 pumps and engines for the 

 work, aggregating about 

 500 horsepower, together 

 with compression tanks 

 and all the essentials for 

 a mammoth indoor hy- 

 draulic laboratory. 



The Largest Indoor Waterfall 

 in the World 



THIS waterfall is not out of doors, nor 

 is it used for the development of 

 power, but it represents the flowing of one 

 hundred tons of water each minute and en- 

 ergy of more than three hundred horse- 

 power. It is part of the laboratory equipment 

 at the Massachusetts Institute of Tech- 

 nology, and illustrates how this 



A 



school teaches by means 

 of commercial quantities 

 under ordinary condi- 

 tions. 



The water here shown 

 has been lifted to an 

 elevated canal, which 

 the students call "the 

 big brook," forty feet 

 above the base of the 

 pump, and returns 

 through a great pen- 

 stock ten feet in diame- 

 ter to the outflow canal. 

 The conduct of water 

 under such pressure and 



VCORD. 



Instead of tying the ends of the 

 cord you simply fasten them in 

 the wire loops. The wire takes 

 the place of the usual knot 



It Fastens Cord Tighter Than You 

 Can Tie It 



PACKAGE tie designed to fasten 

 cord without tying the ends, has been 

 invented by Warren L. Bald, of New York 

 city. The inventor claims that his tie 

 will fasten a cord tighter than any knot 

 ever devised and will hold the cord more 

 securely than a number of knots. 



A spring wire takes the place of the 

 usual knot. Only two operations are 

 necessary to tie the cord. The cord is 

 hooked around the wire 

 loops, and, when a strain 

 is put on these loops, the 

 cord is pulled tighter, the 

 spreading of the wire 

 acting as a lever. The 

 device not only saves the 

 fingers of the person who 

 wraps a large number of 

 packages daily, but with 

 the cord properly se- 

 cured in the wire loops 

 it is impossible for the 

 packages to fall apart. 



