44 



and freedom from mud seemed to favor the iixation of 

 the fry. The slates which occupied a vertical i^osition 

 did not as a whole yield results as satisfactory as those 

 which were placed Hatwise. 



The tiles were not received in time to make a thorough 

 trial, but they seem to he well adapted to retain their 

 coating of mortar, so far as I liave been able to judge 

 from a dozen 'put into the water in the early part of 

 October. 



Shingles will not be adapted to the work, unless they 

 can be protected in some way from the ravages of the 

 ship- worm, as they will not last more than one season at 

 the utmost, even though they were coated with mortar. 

 The diiiicultv in fastenin": the shincides to2:ether is much 

 greater than in arranging the slates, which also have the 

 merit of being indestructible if jDroperly cared for. 



Chaplets of oyster shells were also tried ; the shells 

 were taken, a hole punched through the centre and 

 strung upon galvanized wire. This foriii must be sup- 

 XDorted u]3on a framework or suspended to stakes, as the 

 strings of shells are heavy and very quickly sink to the 

 bottom. They have the merit of being cheaply made 

 since the onlv thina- it is necessarv to buv is the wire, 

 which costs but a trille. I am told by Maj. Ferguson 

 that this tvpe of collector is verv effective as used in 

 practice by the French. Other shells will answer the 

 same purpose, such as those of the white clam, etc. — 

 Another form which was suo:oested bv mv assistant. Mr. 

 AV. P. Sauerhoff, has the advantage of beins: bouvant. 

 This type was made of pine cones, of which we could 

 obtain an abundance near the pond. They were strung 

 on wire in the form of chaplets, six or eight of which 

 were fastened at one end to a stake and weighted down 

 at the other, and arranged so as to radiate like The 

 spokes of a wheel from the stake. The cones however 

 tend to accumulate mud which lodges between the scales; 

 their effectiveness was not determined, since thev were 



