REFRIGERATION AND REFRIGERATOR INSULATION ON BOARD SHIP. 165 
Just at the time these difficulties became apparent, Colonel Marr’s water-proofing pro- 
cess was brought to the writer’s attention, and after numerous experiments with the new 
method it was successfully and practically applied. 
The United States Government has tried out balsa life-preservers, life-buoys, etc., as 
compared with the cork articles, for a period of forty-nine days (twenty-four hours per day), 
at the end of which period the cork preserver had lost all its buoyancy and the balsa pre- 
server still retained the buoyancy stipulated in the government requirements. 
A few years ago, while working on the buoyant-material proposition, it was considered 
that, as balsa, owing to its peculiar structure, was so advantageous for use in buoyancy prod- 
ucts, it might also be adaptable for insulation purposes, and accordingly experiments in that 
direction were begun. The first ice-box made of the new material was on the writer’s motor 
boat, and the results were surprising. All during the hot summer weather, ice was put in 
the box on Friday or Saturday, and on the following Friday or Saturday the temperature in 
the box would still be quite low and some ice still left in the box. 
Naturally, all first work in the line of balsa insulation was more or less crude, and the 
importance of scientific investigation was soon realized. 
It was particularly fortunate that Professor Carpenter became interested in this mate- 
rial. The writer well remembers that when he first spoke to him about this wood, and stated 
that it was all pith and no fiber, he and the gentlemen in his company looked very skeptical. 
However, he was sufficiently interested to visit the Welin plant, intending to remain there 
half an hour, but he spent practically a whole day, and when last seen on that occasion he had 
all his pockets full of balsa, and he has been steadily devoted to the investigation ever since. 
The writer does not pretend to be an expert on insulation or non-conductivity, but looks 
at this material from a practical rather than a scientific viewpoint. 
The principal feature in insulation material is, of course, that it must be a good non- 
conductor, but no doubt in the future engineers will also consider structural strength, and 
the possibility of making up complete homogeneous units will also be considered in judging 
the efficiency and value of insulating material, particularly where it is to be used in making 
ice-boxes and as insulation for buildings, in ships, and in railroad cars. 
The principal consideration is a commercial one; in other words, good engineers always 
try to obtain the highest total efficiency, and commercial men want it and are willing to pay 
for it. 
In shipping, for instance, it is known that almost any ship can be insured if built to cer- 
tain requirements, such as Lloyds, and it can be insured at the lowest rates, except, of 
course, in time of war. All cargo on such ships can also be insured at reasonable rates, ex- 
cept one class, and that is perishable food-stuffs carried in refrigerator compartments, which 
are always carried at the shipper’s or consignee’s risk. Neither the steamship companies 
nor the insurance organizations will place insurance on such goods, except in the event of 
total disaster to the ship. Why? Not because the science of refrigeration has not kept 
pace with the science of naval architecture, but because of the fact that if a break-down oc- 
curs in the refrigerating machinery, the cargo will spoil, as the insulation is not reliable 
_ enough to keep the temperature sufficiently low until the machinery can be repaired and the 
system put to work again. 
The writer had an experience of this kind, many years ago, when on board a meat 
ship running from Australia to London. The machinery broke down while running through 
the Red Sea, and more than half the cargo spoiled in less than twenty-four hours. 
