230 



THE GARDENER'S MONTHLY 



[August, 



to each other. As we have only a tape-Hne to 

 work with, the best way to secure this condition 

 is to divide each half of the chord A C into just 

 as many equal parts as we divide the tangents, 

 numbering them (1), (2), (3), &c., from each tan- 

 gent point. Then from (1) on the tangent range 

 to (1) on the half chords, and lay off" a. Set off 

 4 a from (2) on the tangents to (2) on the half 

 chords, and so on to the end. 



This is one of the sever:il ways of locating a 

 parabola.* It is the one which I have found 

 most convenient in my practice, and it has 

 proved so available that I have felt a desire to 

 make others acquainted with it. Of course it 

 will be understood that there is nothing new or 

 original in it, and most civil engineers are familiar 

 with it, but perhaps others who may have occa- 

 sion to draw the " line of beauty " upon their 

 grounds, and possibly some professional land- 

 scape gardeners may not be ; they will find it 

 applicable in many ways. As already stated, it 

 reverses well ; and it forms one of the most pleas- 

 ing ovals either for carriage-sweep or flower-bed 

 that I have met with. 



*"Vide Henck's Field Book for Engineers." 



EDITORIAL NOTES. 



Lilies. — Lilium canadense is well worth cul" 

 tivating. It is admirably suited to our climate, 

 and is the first to bloom. In Germantown its 

 first blossoms open about the first of July. Others 

 follow through the season. 



Rhododendrons and Ro.se.s. — Rhododendrons 

 are beautiful while they la^st, and uninteresting 

 the rest of the year. Hybrid Perpetual roses, 

 and Gladiolus should be planted among them, 

 and there will be flowers all the year. 



The EL>f Slug. — It is well known that through- 

 out a large part of the United States the elms are 

 skeletonized by a small slug, which renders the 

 trees very unsightly after midsummer. We 

 could find no account of this in the works of the 

 leading entomologists, so set the writer of this 

 at work to observe this season, and this is what 

 he saw: About the middle of May the leaves are 

 seen to be eaten into small holes, and a small 

 beetle, about one-third the size of a potato bee- 

 tle, is found to do the work. It is green, and 

 has a dark olive-colored line running down each 

 wing. It is an extremely active insect, but 



" plays 'possum " at the least suspicion that any- 

 body is after it; and when more frightened, 

 drops as if dead to the ground. It appears to be 

 a species of Galeruca. After two or three weeks 

 the eggs hatch, producing the " slugs " which 

 skeletonize the already riddled leaves. Our en- 

 tomologists would do good service by working 

 the matter up more precisely. 



Lawn from Seed. — The Germantown Telegraph 

 has a well merited compliment to the lawn grass 

 around the government buildings at the Centen- 

 nial Exposition, made under the direction of 

 Mr. William Saunders, from seed sown this 

 spring. There is plenty sown " with oats " in the 

 usual way by othei^s, and with the usual wretched 

 appearance. Why do people sow oats with 

 spring sown lawn grass? Do they know them- 

 selves ? 



Hemlock in Limestone Soils. — From circum- 

 stances that had come before us, we were led to 

 believe that the hemlock -did not do well in 

 some parts of England and elsewhere, because 

 of limestone land. The Coiuifri/ Gentleman notes 

 instances of perfect success with the hemlock in 

 limestone land in Western New York. The 

 poor success of the hemlock at Rochester was 

 one of the reasons for our original conclusion. 

 It would be singular if it should turn out that 

 not even the rhododendron objects to limestone, 

 in spite of the prevalent imjjros.-^ion. 



QUERIES 



Lilium auratum. — You speak of this lily in 

 your last number, and remark that with the ex- 

 ception of L. Parkmani, nothing has been done 

 in the improvement of this superb lily. Did you 

 ever read the Magazine of Htrt'culture f If not, 

 please turn to the volumes for 186(3-67 (vols, 

 xxxii, p. 242, and xxxiii, p. 248). 



As this lily is now in splendid bloom, it oc- 

 curred to us that it would be better to refresh 

 your memory by this reference than to say in 

 plain woi'ds — you must have been living in the 

 woods. Respectfully yours, 



C. M. Hovey. 



Boston, July 4, 1876. 



NEW PLANTS. 



New Tea Rose, Duchess of Edinburgh.— It 

 is to the Messrs. Veitch that we are indebted for 



