ENGINEERING AND ARCHITECTURE. 267 



seasons we make a less favorable appearance, and it seems easy for the botanist 

 to acquaint himself with all the species within his reach ; excepting that as 

 autumn advances the numerous and difficult species of the great genera Aster and 

 Solidago, of which this contiaent is the special home, may exercise his patience 

 and discriminating skill. Among the plants of pecuhar interest from the nature 

 of their distribution in this country, which I have had|the good fortune to meet 

 with, I would mention two rare ferns, Aspidium Zoncliitis, a scarce British fern 

 which has a narrow range over this continent,! and Scolopendrium Officinale, a 

 common British plant, but here very rare, both of which I found on the limestone 

 rocks at Owen's Sound. The following are the plants not found in Gray's list 

 which I have noticed as naturalized in this neighborhood, and which as familiar 

 objects in that country which we always speak of as Home, it is pleasant to add to 

 our list : 



Papaver Rhoeas, Common Poppy. 

 Lychnis flos cuculi, Ragged Robbin. 

 Lychnis vespertina, Evening scented white campion. 



Hieracium pilosella, Mouse ear hawkweed, at Altamore, near Woodstock, North 

 Oxford, C. W., the residence of Thos. J, Cottle, Esq. 

 Rumex acetosa. Sorrel. 



Veronica Buxbaumii. I have not withdrawn this pretty speedwell from the 

 list, although since I made my note it has been introduced by Dr. Gray into his 

 new edition. It is found near Toronto. 

 Cynosurus eri status, Dog't-tail grass. 



I withhold my list only because I have reasonable expectations of greatly 

 increasing it during the coming season. 



IfoTE. — Since the above was in type, I have seen in the Canadian Naturalist 

 and Geologist for February, a list of indigenous^ plants found growing in the 

 neighborhood of Prescott, C. W., by B. Billings, Junr. Setting aside a few mosses 

 and Hepaticse, the number contained in this list is 407, all of which, excepting 

 two or three, are also found in my list. The supplement which the author pro-^ 

 mises. will probably render the difference in extent much less considerable. 



W. H. 



ENGINEERING AND ARCHITECTURE. 



AN IMPROVED FLOOR TO SECUEE GROUND FLOORS AGAINST WET, HEAT, ETC. 



At a meeting of the Canadian institute on the 10th of Api'il, M. Alphonze 

 Coulon, 0. E., read a description of an improved mode of flooring, originally in- 

 troduced by him in Paris, of which the following is an abstract : 



It consists of a level stratum of asphalte cement covering the area of the rooms, 

 laid about J inch in thickness, and before its laying the joists for the support of 

 the boarding have been fitted in a hollow full of asphalte. Such is the improved 

 floor introduced at Paris, in 1852, for the entrepot of Cereales, which M. Coulon 

 superintended, and after several experiments of the same kind he was led to the 

 following conclusions : 



1. The wet is entirely excluded. 



