EocKWOKK FOR Aquakiu.ais, &c.— Pleces of coke dipped in thin Portland 

 cement, and joined together 'with the same material, make the lightest and 

 best rockwork. It should be allowed to harden, and then covered with water 

 (frequently changed) for a week or two. — D. 



Sack Preserving.— A North German paper states that corn and other sacks 

 may be effectually prevented from rotting, and otherwise made to do duty 

 much longer than usual, by simply soaking them in a solution of oak-bark tan. 

 The quantities recommended are 2 lbs. of tan in seventeen or eighteen pints 

 of boiling water, the clear solution being strained off after it has stood an 

 hour. In this the sacks should lie for twenty-four hours, and then be well 

 washed in fresh water and carefully dried. 



Paris Parks and Gardens.— The annual cost of keeping in order the trees, 

 shrubberies, and seats upon the boulevards and in the public squares and 

 gardens of Paris is nearly 2,000,000 fr. It is estimated, says the Builder, that 

 the trees in the avenues and boulevards of Paris number 82,-201 ; those in the . 

 cemeteries, 10,400; and those in the squares and courtyards of various 

 buildings, 8,300. There are also 8,000 seats for the accommodation of the 

 public. The expense of keeping up all the extra-mural recreation grounds, 

 exclusive of the Bois de Boulogne and the Bois de Vincennes, is rather more 

 than 300,000 fr. 



British Oak (Quercus robur) in A^ierica,— On the 6th of August the writer 

 measured a large number of oak growths, which were over four feet, and still 

 growing. The variety was Qaercus rohur. The oak does not grow near as 

 slow in America as many suppose. Mr. Hoopes, of West Chester, has one— 

 a variety of Quercus macrocarpa—thsbt is only twelve years old, and is now 

 17 feet high and 17 inches in circumference. — C. D. 



A Handsome Prize.— The Government of India has renewed the offer of a 

 reward for the best process or machine for separating the fibre of the Bdhmeria 

 nivea. The reward is fifty thousand rupees, and a smaller reward of ten 

 thousand rupees will be given to the second best machine or process. The 

 amount is well worth competing for, but persons desiring to do so must 

 notify their intention befor the 31st December, 1878, The trials will beheld 

 at Sahranpore, in the North-West Provinces, in the months of August and 

 September, 1879. 



The Deciduous Cypress.— This tree is, where it flourishes, an object of 

 much beauty. And for the information of those interested in such trees, I beg 

 to say that there are two— and those the largest I ever saw of that variety- 

 growing in the grounds here. The larger of the two stands about lOO feet 

 high, and at four feet from the ground measures 7 feet 6 inches in circum- 

 ference. The trunk is comparatively straight and clean for about forty feet, 

 at which point it assumes two leaders, one of which was broken off some years 

 ao-o with the wind, and from the same cause it is mlii'ts soine of its branches, 



