12 N. H. AGR. EXPERIMENT STATION [Bulletin 204 



neath had become infested. Baseboards along the partitions of this floor 

 were removed so as to ascertain whether the insects had extended their work 

 into the partitions above. In order to determine this a section 6 inches long 

 was sawed out of every other upright of these partitions, next to the floor. 

 These sections gave uniform evidence that the work of the termit«s had ceased 

 at about the floor level. Apparently, they had not yet had time to extend 

 their ravages into the first floor partitions. 



The task of eradication of the insects from the administration building 

 now began. 



All of the partitions and other material that had been taken out of the 

 basement and first floor were burned. The spaces that were left in the con- 

 crete basement floor where the partitions had projected through to the ground 

 beneath, were filled with cement so that the entire basement presented a 

 continuous floor of concrete extending to the outer walls. The finings of 

 hand holes were removed and burned. 



Staii-ways were taken apart, or the lath and plaster removed far enough 

 to disclose the upper limits to which the termites had mined. They were 

 reconstructed so as to rest on the concrete floor. The infested boards in 

 the boiler room were removed and burned. 



It was necessary to remove two of the main supporting beams. In order 

 to do this the central part of the building was supported with temporary 

 timbers; the large beams — -or what was left of them— were taken down from 

 the brick pillars; and new beams were got into position by placing planks 

 side by side vertically and bolting these together. 



There was no way of making really certain that all material carrying ter- 

 mites had been removed. On the contrary, it was more than likely that 

 some of the flooring and other wooden parts still held large numbers of the 

 insect. It will be noted that the laundry for the hospital was located in 

 this basement. Both as to heat and moisture this furnished conditions well 

 suited to the further increase of the pest, if fivtng specimens remained within 

 the building. 



In this emergency it was decided to attempt extermination of any termites 

 remaining in the basement by means of heat. 



Experiments were first carried out to determine the time and temperature 

 factors that would be required for killing the pests within timbers. It was 

 necessary not only to know what temperature would be required and for how 

 long a period where the termites were more or less directly exposed to the heat, 

 but also to determine what factor should be taken into account in order to 

 make certain that killing would take place within heavy supporting beams, 

 since there was serious probability that beams that had not been removed 

 contained numbers of the termites. 



Blocks of spruce wood 10 x 10 x 10 were prepared. Each block was sawed 

 in haK and bolts arranged so that the two halves could be rejoined securely. 

 The surface of the two halv&s, where they were joined, was planed. A square 

 of asbestos measuring 10 in. each way and 1-4 in. thick was fitted between 

 the two halves. At the center of the asbestos a hole was cut, measuring 1 in. 

 square. When the two halves were joined, with the asbestos board between 



