828 Transactions of the American Institute. 



at Pliiladelphia. The aggregate, during forty years, at each station, 

 exhibit the following ratios of weekly rainfall : 



Surrey. Philadelphia. 



"Week of new moon 98.2 97.G 



Week of iirst quarter 103.1 100.3 



Week of full moon 97.4 95.8 



Week of last quarter 101.4 106.3 



Mr. Chase refers also to observations at Mussoorie, on the southern 

 range of the Ilinialaya mountains, the mean results of which for thir- 

 teen years are as follows : 



Average 

 daily fall. KatioB. 



Day of new moon 402 86.2 



Day of iirst quarter 535 114. Y 



Day of full moon 399 85.6 



Day of last qnarter 529 113.5 



Laying Railway Tracks by MAcniNERY. 

 The San Francisco Alta contains the following: The railroad 

 track-layer is an indubitable and decided success. It is now working 

 along regularly at the rate of a mile a day, and it will do better 

 when several small defects are remedied. Some of its work has been 

 done at the rate of two miles in twelve hours ; but one mile is con- 

 sidered its present working capacity. The contractor and directors 

 of the Yallejo and Sacramento railroad, although most of them were 

 skeptical, and some quite dissatisfied about the delays in getting it 

 into operation, give it the highest praise, and have made their 

 arrangements in reliance upon it. The machine is a car sixty feet 

 long and ten feet wide. It has a small engine on board for handling 

 ties and rails. The ties are carried on a common freight car behind, 

 and conveyed by an endless chain over the top of the machine, laid 

 down in their places on the track, and when enough are laid, a rail 

 is put down on each side in a proper position, and spiked down. 

 The track-layer then advances, and keeps on its work until the load 

 of ties and rails is exhausted, when other car loads are brought. 

 The machine is driven ahead by a locomotive, and the work is done 

 60 rapidly that sixty men are required to wait on it ; but they do 

 more work than twice as many could do b}' the old system, and the 

 work is done quite as well. The chief contractor of the road gives 

 it as his opinion that when the machine is improved by making a 

 few changes in the method of handling rails and ties, the necessity 

 of which changes is now apparent, it will be able to put down live 

 or six miles per day unquestionably. This will render it possible to 



