482 





AMERICAN FORESTRY 



a good one is used, it Will nearly double the period of 

 service which a roof of good shingles will give. 



In a former article of this series, mention was made 

 of a barn in 

 West Virginia 

 whose white 

 pine shingle 

 roof remained 

 in place 102 

 years and then 

 collapsed under 

 an extraordi- 

 nary fall of 

 sno w . The 

 original nails 

 were still good, 

 and not a 

 shingle had be- 

 come loose on 

 account of the 

 nails rusting 

 off. So re- 

 markable was 

 this, that the 

 local historian 

 of the neigh- 

 borhood inves- 



, , . The waUs of this building are 120 feet apart anj$i the arched wooden trusses span the space between 



tigated the Ori- and sustain the enormous weight of the roof. Such use constitutes a triumph for wood under exacting 



f , .. conditions. This truss is as good as one of steel and much cheaper. Photograph by the National 



gin 01 the nailS, Lumber Manufacturers' Association, Chicago. 



and by examining old diaries kept by William Parsons, 

 the builder of the barn, it was ascertained that the 

 nails had been hammered from bar iron in the farmer's 



black smith 

 shop by a negro 

 slave, "during 

 rainy weather." 

 That the work 

 was done dur- 

 i n g rainy 

 weather proba- 

 bly had noth- 

 ing to do with 

 the lasting 

 p r o p e r ty of 

 the nails ; but 

 the fact that 

 wrought iron 

 nails lasted 

 more than a 

 century in the 

 most exposed 

 position imag- 

 i n a b 1 e, may 

 contain a hint 

 of value to 

 present day 

 manufacturers 

 of shingle nails. 



ROOF TRUSSES REACHING FROM WALL TO WALL 



BLACK WALNUT FROM THE GUGGENHEIM ESTATE OFFERED TO THE GOVERNMENT 



TN offering the black walnut trees on his Port Washing- 

 -*- ton (L. I.) estate to the Government for the manu- f 

 facture of airplane propellers, says the New York Sun, 

 William Guggenheim has aroused greater interest in the 

 value of those trees for commercial use than perhaps 

 has been done for over half a century. The prin- 

 cipal source of the black walnut was in the West and 

 before its popularity waned so many thousands of the 

 walnut trees were cut down that today they are almost 

 as extinct as the American buffalo. 



Mr. Guggenheim, who is chairman of the Army and 

 Navy Committee of the American Defense Society, said 

 that he had recently h, a d a census taken of his black 

 walnut trees and discovered that he had about 200. 



"My black walnuts vary from one foot to three and a 

 half feet in circumference near the ground," said Mr. 

 Guggenheim. "I believe they were all planted many years 

 ago by former owners. As the tree* is slow growing, the 

 largest specimens are probably at least 75 years old. Per- 

 haps only a portion will be available for propellers, but 

 if any of them will be of assistance in aircraft production 

 they will be cut down. 



"Before the trees are taken I presume they will be 

 looked over by some one designated by the Aircraft Com- 

 mittee. My idea is to have those selected as available for 

 use sold to manufacturers of airplanes and have the 

 money placed in a fund to be divided by the Red Cross 

 and some other organization." 



So far as could be ascertained from landscape archi- 

 tects who are familiar with Long Island estates William 

 Guggenheim's Port Washington place contains the largest 

 number of black walnut trees within a single ownership 

 on Long Island. 



G. Douglas Wardrop, editor of Aerial Age, in dis- 

 cussing the use of black walnut for airplanes, said that 

 next to mahogany it is doubtless the best wood for pro- 

 pellers, but so little of it is to be had that he doubted 

 whether all the black walnuts on Long Island would be 

 sufficient for more than a few score of propellers. 



"You must remember," explained Mr. Wardrop, "that 

 for a satisfactory propeller you want a plank eight feet 

 or more in length and wide enough at the ends to give a 

 14-inch blade. There are usually five layers of these 

 eight-foot propeller blades, firmly glued together, and 

 oak is being used for some of the inner pieces. I do not 

 think there are many black walnuts in the country that 

 would provide many solid eight-foot planks over 14 

 inches wide. Mahogany, on account of its strength and 

 solid grain, has always been the favorite wood for air- 

 plane propellers and, with few exceptions, is being used 

 for all our best airplanes. We have been getting a very 

 satisfactory supply both from South America and the 

 west coast of Africa, the African mahogany being the 

 better for propeller use. The time is coming, however, 

 when our airplanes will probably be equipped with metal 

 propellers. Germany has used them very successfully." 



