662 REPORTS ON THE STATE OF SCIENCE. 



H. Special Measuuejients. 



1 . Span of arms. 



2. Weight. 



Where it is possible to do so the weight of the individual 

 should be taken after he has divested himself of his clothes. 

 The following symbols may be used to indicate how the weight 

 has been ascertained : — 



W^ With clothes and boots. 



W-. With clothes but without the boots. 



W"*. Without both clothes and boots, 



3. TeeLh. 



4. Finger-prints. 



INSTRUMENTS. 



Weighing Machines. 



The two leading types of personal weighing machine on the market 

 are : (1) steelyard weighing machines, and (2) spring weighing machines. 



I. Steelyard Weighing Machines, 



In the most convenient form of steelyard weighing machine the steel- 

 yard is supported on the top of a pillar on a level with the eyes of the 

 observer. The platform, on which the person to be weighed stands, is 

 supported by knife- edges on levers housed in the base of the machine, and 

 connected by a rod passing up the centre of the pillar to the short end of 

 the steelyard. 



A personal weigiiing machine of this type is made by W. & J. Avery, 

 Ltd., Soho Foundry, Birmingham. It weiglis up to 21 stones by single 

 ounces. It is also graduated to weigh in metric measure. In weighing 

 with this machine sufficient loose weights are first placed on a disc 

 suspended from the outer end of the steelyard, the final adjustment being 

 made by a small weight which slides on the steelyard. Another machine 

 without loose weights is also made by the same makers, 



A steelyard machine by Day tt Millward, 39 Duke Street, Aldgate, 

 London, weighs up to 12 stones without the employment of loose 

 weights. The steelyard consists of two parallel graduated bars, on the 

 lower one of which slides a heavy weight for weighing the larger units, 

 while a light weight slides on the upper bar for weighing the smaller 

 units and making the final adjustment. By suspending a loose weight 

 on the end of the steelyard this machine is made capable of weighing up 

 to 24 stones. The steelyard is graduated to weigh botli in Engli.sh and 

 li'rench measure, 



II. Spring Weighing Machines. 



Spring weighing machines are not so reliable as steelyard machines, 

 because they are liable to be deranged by shocks or by leaving a heavy 

 weight for a long time on the spring. They have, however, a great 

 advantage over the steelyard machines in that persons can be weighed 

 much more rapidly, and this is a quality of considerable importance when 

 large numbers of persons have to be weighed in a short time, If th^sa 



