4H 



THE POPULAR SCIENCE MONTHLY. 



with which legend declared that it attracted 

 its sympathizing victims to the bank of the 

 stream, are highly decorative, if not beauti- 

 ful. The head, narrow and flat, resembles 

 the head of a snake ; the nose is sharp, and 

 the fixed and motionless eyes are of the palest 

 dusty gold, set in a short, horny pillar of 

 a deeper golden brown. The crocodile's coat 

 of armor is less complete than that of the 

 alligator, and its quick, vivacious movements 

 make it far more troublesome to the keepers 

 when the tank has to be refilled and cleaned 

 than the big alligators, which will allow 

 themselves to be used as stepping-stones as 

 the water ebbs away. " The heloderm, a fat 

 and torpid lizard from Arizona, is supposed 

 to be the sole existing member of its tribe, 

 which possesses not only the poison glands 

 that exist in most of the toads, but also the 

 true poison teeth, with a channel for the 

 emission of the venom. The lizard is about 

 a foot and a half long, with a fat, fleshy body, 

 a round tail ending in a blunt point, and a flat 

 head with squared sides, resembling a small 

 padlock. The whole body is covered with a 

 curious coat of scales, like black and pink 

 beads, arranged in an arabesque pattern. In 

 its daily life it is a dull and stupid creature, 

 feeding mainly on eggs, which it breaks and 

 laps with its tongue. Its first and only vic- 

 tim was a guinea-pig that was put into its 

 cage with a view to testing the reports as 

 to its poisonous nature, which were by no 

 means universally credited. The lizard bit 

 the guinea-pig in the leg, and the animal died 

 in a minute and a half, almost as soon as 

 after the bite of a cobra." 



Fresh Air for Legislators. The Speaker 

 of the British House of Commons recently 

 pointed out a great need of the house over 

 which he presides, and of other legislative 

 bodies as well. Having arrived at Leaming- 

 ton for a little rest, he expressed his pleasure 

 at finding himself there, " under the open air 

 of heaven," after scenes of great anxiety and 

 responsibility. There are very few men, as 

 the Lancet remarks, commenting on this ob- 

 servation, having business of their own to 

 attend to who can stand the work of Tarlia- 

 ment from three in the afternoon till twelve 

 at night without breaking down. The air of 

 the house whatever the " scientific ventila- 

 tion " is not the " open air of heaven." In 



addition to the want of air and want of space, 

 are the temperature of discussion and the 

 tension of highly strung men greatly differ- 

 ing in opinion. The Speaker is quoted as 

 saying that the deterioration of members in 

 health is evident from day to day, and that 

 he sees men gradually becoming degenerate. 

 He has been told by a cabinet minister, who is 

 a peer, that he can recognize members of the 

 House of Commons " by their pallid counte- 

 nances," and can distinguish between them 

 and members of the House of Lords. " It is 

 the height of unreason to expect good legis- 

 lation under such absurd conditions." 



Requisites of a Flying Machine. The 



principle seems to be accepted now by most 

 of the students of aerial navigation that the 

 successful air vessel, instead of a balloon, 

 must be a body heavier than the air, and 

 must be sustained as well as propelled in 

 some way similar to that by which a bird 

 flies. This principle was fully set forth in 

 The Popular Science Monthly for January, 

 1892, by M. G. Trouv6, whose aviator, 

 therein described, had wings acting almost 

 precisely like those of a bird. M. Trouve 

 proposed for his machine an ingenious motor, 

 which was to be actuated by the alternate 

 compression and expansion of a gas in a 

 Bourdon tube. Previous to M. Trouve's 

 paper, articles setting forth the principle of 

 " heavier than the air " had been published 

 by Mr. 0. Chanute, Prof. S. P. Langley, and 

 Mr. H. S. Maxim, and several have been 

 published since in American magazines and 

 journals. A writer who discusses the sub- 

 ject of aerial navigation in the Boston Herald 

 raises the objection to a wing-motion, such 

 as M. Trouve's aviator contemplates, that 

 the power needed to secure the velocity 

 which an oscillating machine would require 

 would probably cause the machine to destroy 

 itself by the violence of its own vibrations. 

 He proposes instead to depend on an aero- 

 plane to hold the machine in the air, and to 

 use a screw propeller as a source of motive 

 power. He would pattern and proportion 

 the aeroplane after the position of the mo- 

 tionless wings of a loon in scaling descent, 

 as after they have been paralyzed by a shot 

 hitting the brain ; place the screw in front, 

 on the principle that an arrow can not fly 

 except with its heavier end foremost, and 



