118 



SCIENCE 



[N. S. Vol. XXX. No. 760 



we all know that Mary is a " typhoid carrier," 

 and a dangerous one hy reason of her occupa- 

 tion as a cook ; but she is only one among 

 many such " carriers " and it is scarcely jus- 

 tice to place upon her alone the burden that 

 should be shared by her entire class. 



Of all those who recover from typhoid fever 

 something like four per cent, carry about with 

 them the germs of the disease for long periods 

 of time. They are " carriers " in fact, and 

 can, like Mary, become centers for secondary 

 infection. There are at the present moment 

 probably 560 such persons in the state of New 

 York, representing four per cent, of the 14,- 

 000 cases of typhoid fever occurring during 

 the past year. How many must be added to 

 that number to allow for the " hold-overs " 

 coming down from previous years it would be 

 hard to guess. Others will be added during the 

 year to come. 



We can not keep in detention all these 

 people, then why single out and imprison one. 



Typhoid carriers are dangerous when they 

 are possessed of uncleanly personal habits, and 

 they become more so when their occupations 

 have to do with the preparation of food. 



It would be eminently wise to instruct a 

 " carrier " as to the danger lurking in human 

 dejecta and to insist upon the necessity for 

 great personal cleanliness. It might be also 

 well for the authorities to direct that such a 

 person should not be engaged in the prepara- 

 tion of food ; but beyond " education " and an 

 order for " change of occupation " it is scarcely 

 practical or fair to go. 



W. P. Mason 



Eensselaer Polytechnic Institute, 

 July 1, 1909 



QVOTATIO'NS 

 MR. Latham's aeroplane 

 After a comparatively short training, Mr. 

 Hubert Latham has brought the Antoinette 

 monoplane from obscurity into serious rivalry 

 with the Wright machine as regards duration 

 of flight, while it is easily superior in speed. 

 He has also shown that it can be flown in 

 windy weather, and the ease with which he 

 controls it quite upsets the theory held by the 



bi-planists that the monoplane is exceedingly 

 difficult to manage. Nevertheless, when the 

 experience of Mr. Latham is placed alongside 

 that of the many other monoplanists, who so 

 far have not been particularly successful, the 

 point is demonstrated that the human element 

 counts for much. It would appear that Mr. 

 Latham is something of a genius in naviga- 

 ting aerial machines. 



The Antoinette monoplane, which is de- 

 signed by M. Levavasseur, consists of a cen- 

 tral skiff-like body, from each side of which 

 a main plane springs at a slight upward tilt. 

 The single propeller is mounted in front of 

 the central body, and close behind is the mo- 

 tor. In a well to the rear of this the pilot is 

 comfortably situated, his position allowing 

 him a clear look-out, and affording a certain 

 degree of protection not noticeable in other 

 machines. Indeed, Mr. Latham claims that 

 he is very safe from injury in this machine, 

 being well protected by the planes and the 

 body of the vessel. 



At the rear of the main body are vertical 

 equalizing fins, two vertical rudders, and a 

 horizontal elevator for giving upward or 

 downward direction. The lines of the body 

 are very clean, the total bearing surface is re- 

 markably small, and there is an absence of the 

 many stays and members which, in the bi- 

 plane especially, lead to increased head re- 

 sistance and consequent loss of speed. At the 

 rear end of each main plane is a flexible ex- 

 tension, which can be given a varying angle 

 of incidence for purposes of stability. 



The under-frame is a clever piece of work. 

 The chassis rests on two wheels placed close 

 together, and a forward extension of this 

 frame takes the form of a runner, which ig 

 designed to receive the first shock of landing 

 and thus save the wheels from buckling 

 strains. The combination of sledge runner 

 and wheels in the Antoinette enables the aero- 

 plane to be started without the use of extran- 

 eous mechanism, whilst it allows landing to 

 be effected at speeds which would smash any 

 ordinary wheel. 



The control of the Antoinette machine is 

 by means of side wheels, those at one side 



